diff --git a/backend/ddang/src/main/java/com/ddang/ddang/chat/application/ChatRoomService.java b/backend/ddang/src/main/java/com/ddang/ddang/chat/application/ChatRoomService.java
index efb3d78d6..8e91c6c0a 100644
--- a/backend/ddang/src/main/java/com/ddang/ddang/chat/application/ChatRoomService.java
+++ b/backend/ddang/src/main/java/com/ddang/ddang/chat/application/ChatRoomService.java
@@ -9,6 +9,7 @@
 import com.ddang.ddang.chat.application.dto.CreateChatRoomDto;
 import com.ddang.ddang.chat.application.dto.ReadChatRoomWithLastMessageDto;
 import com.ddang.ddang.chat.application.dto.ReadParticipatingChatRoomDto;
+import com.ddang.ddang.chat.application.event.CreateReadMessageLogEvent;
 import com.ddang.ddang.chat.application.exception.ChatRoomNotFoundException;
 import com.ddang.ddang.chat.application.exception.InvalidAuctionToChatException;
 import com.ddang.ddang.chat.application.exception.InvalidUserToChat;
@@ -22,6 +23,7 @@
 import com.ddang.ddang.user.domain.User;
 import com.ddang.ddang.user.domain.repository.UserRepository;
 import lombok.RequiredArgsConstructor;
+import org.springframework.context.ApplicationEventPublisher;
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
 
@@ -35,6 +37,7 @@ public class ChatRoomService {
 
     private static final Long DEFAULT_CHAT_ROOM_ID = null;
 
+    private final ApplicationEventPublisher messageLogEventPublisher;
     private final ChatRoomRepository chatRoomRepository;
     private final ChatRoomAndImageRepository chatRoomAndImageRepository;
     private final ChatRoomAndMessageAndImageRepository chatRoomAndMessageAndImageRepository;
@@ -51,9 +54,15 @@ public Long create(final Long userId, final CreateChatRoomDto chatRoomDto) {
                                                      );
 
         return chatRoomRepository.findChatRoomIdByAuctionId(findAuction.getId())
-                                 .orElseGet(() ->
-                                         persistChatRoom(findUser, findAuction).getId()
-                                 );
+                                 .orElseGet(() -> createChatRoom(findUser, findAuction));
+    }
+
+    private Long createChatRoom(final User findUser, final Auction findAuction) {
+        final ChatRoom persistChatRoom = persistChatRoom(findUser, findAuction);
+
+        messageLogEventPublisher.publishEvent(new CreateReadMessageLogEvent(persistChatRoom));
+
+        return persistChatRoom.getId();
     }
 
     private ChatRoom persistChatRoom(final User user, final Auction auction) {
diff --git a/backend/ddang/src/main/java/com/ddang/ddang/chat/application/LastReadMessageLogEventListener.java b/backend/ddang/src/main/java/com/ddang/ddang/chat/application/LastReadMessageLogEventListener.java
new file mode 100644
index 000000000..5c67a1089
--- /dev/null
+++ b/backend/ddang/src/main/java/com/ddang/ddang/chat/application/LastReadMessageLogEventListener.java
@@ -0,0 +1,39 @@
+package com.ddang.ddang.chat.application;
+
+import com.ddang.ddang.chat.application.event.CreateReadMessageLogEvent;
+import com.ddang.ddang.chat.application.event.UpdateReadMessageLogEvent;
+import com.ddang.ddang.chat.application.exception.ReadMessageLogNotFoundException;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.stereotype.Component;
+import org.springframework.transaction.annotation.Propagation;
+import org.springframework.transaction.annotation.Transactional;
+import org.springframework.transaction.event.TransactionalEventListener;
+
+@Slf4j
+@Component
+@RequiredArgsConstructor
+public class LastReadMessageLogEventListener {
+
+    private final LastReadMessageLogService lastReadMessageLogService;
+
+    @TransactionalEventListener
+    @Transactional(propagation = Propagation.REQUIRES_NEW)
+    public void create(final CreateReadMessageLogEvent createReadMessageLogEvent) {
+        try {
+            lastReadMessageLogService.create(createReadMessageLogEvent);
+        } catch (final IllegalArgumentException ex) {
+            log.error("exception type : {}, ", ex.getClass().getSimpleName(), ex);
+        }
+    }
+
+    @TransactionalEventListener
+    @Transactional(propagation = Propagation.REQUIRES_NEW)
+    public void update(final UpdateReadMessageLogEvent updateReadMessageLogEvent) {
+        try {
+            lastReadMessageLogService.update(updateReadMessageLogEvent);
+        } catch (final ReadMessageLogNotFoundException ex) {
+            log.error("exception type : {}, ", ex.getClass().getSimpleName(), ex);
+        }
+    }
+}
diff --git a/backend/ddang/src/main/java/com/ddang/ddang/chat/application/LastReadMessageLogService.java b/backend/ddang/src/main/java/com/ddang/ddang/chat/application/LastReadMessageLogService.java
new file mode 100644
index 000000000..abba0d301
--- /dev/null
+++ b/backend/ddang/src/main/java/com/ddang/ddang/chat/application/LastReadMessageLogService.java
@@ -0,0 +1,46 @@
+package com.ddang.ddang.chat.application;
+
+import com.ddang.ddang.chat.application.event.CreateReadMessageLogEvent;
+import com.ddang.ddang.chat.application.event.UpdateReadMessageLogEvent;
+import com.ddang.ddang.chat.application.exception.ReadMessageLogNotFoundException;
+import com.ddang.ddang.chat.domain.ChatRoom;
+import com.ddang.ddang.chat.domain.ReadMessageLog;
+import com.ddang.ddang.chat.domain.repository.ReadMessageLogRepository;
+import com.ddang.ddang.user.domain.User;
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.util.List;
+
+@Service
+@Transactional(readOnly = true)
+@RequiredArgsConstructor
+public class LastReadMessageLogService {
+
+    private final ReadMessageLogRepository readMessageLogRepository;
+
+    @Transactional
+    public void create(final CreateReadMessageLogEvent createReadMessageLogEvent) {
+        final ChatRoom chatRoom = createReadMessageLogEvent.chatRoom();
+        final User buyer = chatRoom.getBuyer();
+        final User seller = chatRoom.getAuction().getSeller();
+        final ReadMessageLog buyerReadMessageLog = new ReadMessageLog(chatRoom, buyer);
+        final ReadMessageLog sellerReadMessageLog = new ReadMessageLog(chatRoom, seller);
+
+        readMessageLogRepository.saveAll(List.of(buyerReadMessageLog, sellerReadMessageLog));
+    }
+
+    @Transactional
+    public void update(final UpdateReadMessageLogEvent updateReadMessageLogEvent) {
+        final User reader = updateReadMessageLogEvent.reader();
+        final ChatRoom chatRoom = updateReadMessageLogEvent.chatRoom();
+        final ReadMessageLog messageLog = readMessageLogRepository.findBy(reader.getId(), chatRoom.getId())
+                                                                  .orElseThrow(() ->
+                                                                          new ReadMessageLogNotFoundException(
+                                                                                  "메시지 조회 로그가 존재하지 않습니다."
+                                                                          ));
+
+        messageLog.updateLastReadMessage(updateReadMessageLogEvent.lastReadMessage().getId());
+    }
+}
diff --git a/backend/ddang/src/main/java/com/ddang/ddang/chat/application/MessageService.java b/backend/ddang/src/main/java/com/ddang/ddang/chat/application/MessageService.java
index 35493d0f5..9d9045ecb 100644
--- a/backend/ddang/src/main/java/com/ddang/ddang/chat/application/MessageService.java
+++ b/backend/ddang/src/main/java/com/ddang/ddang/chat/application/MessageService.java
@@ -3,6 +3,7 @@
 import com.ddang.ddang.chat.application.dto.CreateMessageDto;
 import com.ddang.ddang.chat.application.dto.ReadMessageDto;
 import com.ddang.ddang.chat.application.event.MessageNotificationEvent;
+import com.ddang.ddang.chat.application.event.UpdateReadMessageLogEvent;
 import com.ddang.ddang.chat.application.exception.ChatRoomNotFoundException;
 import com.ddang.ddang.chat.application.exception.MessageNotFoundException;
 import com.ddang.ddang.chat.application.exception.UnableToChatException;
@@ -15,7 +16,6 @@
 import com.ddang.ddang.user.domain.User;
 import com.ddang.ddang.user.domain.repository.UserRepository;
 import lombok.RequiredArgsConstructor;
-import lombok.extern.slf4j.Slf4j;
 import org.springframework.context.ApplicationEventPublisher;
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
@@ -25,10 +25,10 @@
 @Service
 @Transactional(readOnly = true)
 @RequiredArgsConstructor
-@Slf4j
 public class MessageService {
 
-    private final ApplicationEventPublisher messageEventPublisher;
+    private final ApplicationEventPublisher messageLogEventPublisher;
+    private final ApplicationEventPublisher messageNotificationEventPublisher;
     private final MessageRepository messageRepository;
     private final ChatRoomRepository chatRoomRepository;
     private final UserRepository userRepository;
@@ -53,16 +53,14 @@ public Long create(final CreateMessageDto dto, final String profileImageAbsolute
 
         final Message persistMessage = messageRepository.save(message);
 
-        messageEventPublisher.publishEvent(new MessageNotificationEvent(persistMessage, profileImageAbsoluteUrl));
+        messageNotificationEventPublisher.publishEvent(new MessageNotificationEvent(persistMessage, profileImageAbsoluteUrl));
 
         return persistMessage.getId();
     }
 
     public List<ReadMessageDto> readAllByLastMessageId(final ReadMessageRequest request) {
-        if (!userRepository.existsById(request.messageReaderId())) {
-            throw new UserNotFoundException("지정한 아이디에 대한 사용자를 찾을 수 없습니다.");
-        }
-
+        final User reader = userRepository.findById(request.messageReaderId())
+                                          .orElseThrow(() -> new UserNotFoundException("지정한 아이디에 대한 사용자를 찾을 수 없습니다."));
         final ChatRoom chatRoom = chatRoomRepository.findById(request.chatRoomId())
                                                     .orElseThrow(() -> new ChatRoomNotFoundException(
                                                             "지정한 아이디에 대한 채팅방을 찾을 수 없습니다."));
@@ -77,6 +75,12 @@ public List<ReadMessageDto> readAllByLastMessageId(final ReadMessageRequest requ
                 request.lastMessageId()
         );
 
+        if (!readMessages.isEmpty()) {
+            final Message lastReadMessage = readMessages.get(readMessages.size() - 1);
+
+            messageLogEventPublisher.publishEvent(new UpdateReadMessageLogEvent(reader, chatRoom, lastReadMessage));
+        }
+
         return readMessages.stream()
                            .map(message -> ReadMessageDto.from(message, chatRoom))
                            .toList();
diff --git a/backend/ddang/src/main/java/com/ddang/ddang/chat/application/dto/ReadChatRoomWithLastMessageDto.java b/backend/ddang/src/main/java/com/ddang/ddang/chat/application/dto/ReadChatRoomWithLastMessageDto.java
index 36e3d0382..b52e55a9e 100644
--- a/backend/ddang/src/main/java/com/ddang/ddang/chat/application/dto/ReadChatRoomWithLastMessageDto.java
+++ b/backend/ddang/src/main/java/com/ddang/ddang/chat/application/dto/ReadChatRoomWithLastMessageDto.java
@@ -11,6 +11,7 @@ public record ReadChatRoomWithLastMessageDto(
         ReadAuctionInChatRoomDto auctionDto,
         ReadUserInChatRoomDto partnerDto,
         ReadLastMessageDto lastMessageDto,
+        Long unreadMessageCount,
         boolean isChatAvailable
 ) {
 
@@ -22,12 +23,14 @@ public static ReadChatRoomWithLastMessageDto of(
         final User partner = chatRoom.calculateChatPartnerOf(findUser);
         final Message lastMessage = chatRoomAndMessageAndImageDto.message();
         final AuctionImage thumbnailImage = chatRoomAndMessageAndImageDto.thumbnailImage();
+        final Long unreadMessages = chatRoomAndMessageAndImageDto.unreadMessageCount();
 
         return new ReadChatRoomWithLastMessageDto(
                 chatRoom.getId(),
                 ReadAuctionInChatRoomDto.of(chatRoom.getAuction(), thumbnailImage),
                 ReadUserInChatRoomDto.from(partner),
                 ReadLastMessageDto.from(lastMessage),
+                unreadMessages,
                 chatRoom.isChatAvailablePartner(partner)
         );
     }
diff --git a/backend/ddang/src/main/java/com/ddang/ddang/chat/application/event/CreateReadMessageLogEvent.java b/backend/ddang/src/main/java/com/ddang/ddang/chat/application/event/CreateReadMessageLogEvent.java
new file mode 100644
index 000000000..fec66ac3a
--- /dev/null
+++ b/backend/ddang/src/main/java/com/ddang/ddang/chat/application/event/CreateReadMessageLogEvent.java
@@ -0,0 +1,6 @@
+package com.ddang.ddang.chat.application.event;
+
+import com.ddang.ddang.chat.domain.ChatRoom;
+
+public record CreateReadMessageLogEvent(ChatRoom chatRoom) {
+}
diff --git a/backend/ddang/src/main/java/com/ddang/ddang/chat/application/event/UpdateReadMessageLogEvent.java b/backend/ddang/src/main/java/com/ddang/ddang/chat/application/event/UpdateReadMessageLogEvent.java
new file mode 100644
index 000000000..8fd1cde98
--- /dev/null
+++ b/backend/ddang/src/main/java/com/ddang/ddang/chat/application/event/UpdateReadMessageLogEvent.java
@@ -0,0 +1,8 @@
+package com.ddang.ddang.chat.application.event;
+
+import com.ddang.ddang.chat.domain.ChatRoom;
+import com.ddang.ddang.chat.domain.Message;
+import com.ddang.ddang.user.domain.User;
+
+public record UpdateReadMessageLogEvent(User reader, ChatRoom chatRoom, Message lastReadMessage) {
+}
diff --git a/backend/ddang/src/main/java/com/ddang/ddang/chat/application/exception/ReadMessageLogNotFoundException.java b/backend/ddang/src/main/java/com/ddang/ddang/chat/application/exception/ReadMessageLogNotFoundException.java
new file mode 100644
index 000000000..45eb4623f
--- /dev/null
+++ b/backend/ddang/src/main/java/com/ddang/ddang/chat/application/exception/ReadMessageLogNotFoundException.java
@@ -0,0 +1,8 @@
+package com.ddang.ddang.chat.application.exception;
+
+public class ReadMessageLogNotFoundException extends IllegalArgumentException {
+
+    public ReadMessageLogNotFoundException(final String message) {
+        super(message);
+    }
+}
diff --git a/backend/ddang/src/main/java/com/ddang/ddang/chat/domain/ReadMessageLog.java b/backend/ddang/src/main/java/com/ddang/ddang/chat/domain/ReadMessageLog.java
new file mode 100644
index 000000000..c741228a4
--- /dev/null
+++ b/backend/ddang/src/main/java/com/ddang/ddang/chat/domain/ReadMessageLog.java
@@ -0,0 +1,49 @@
+package com.ddang.ddang.chat.domain;
+
+import com.ddang.ddang.user.domain.User;
+import jakarta.persistence.CascadeType;
+import jakarta.persistence.Entity;
+import jakarta.persistence.FetchType;
+import jakarta.persistence.ForeignKey;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.GenerationType;
+import jakarta.persistence.Id;
+import jakarta.persistence.JoinColumn;
+import jakarta.persistence.ManyToOne;
+import jakarta.persistence.OneToOne;
+import lombok.AccessLevel;
+import lombok.EqualsAndHashCode;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.ToString;
+
+@Entity
+@NoArgsConstructor(access = AccessLevel.PROTECTED)
+@Getter
+@EqualsAndHashCode(of = "id", callSuper = false)
+@ToString(of = {"id", "lastReadMessageId"})
+public class ReadMessageLog {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+
+    @ManyToOne(fetch = FetchType.LAZY, cascade = {CascadeType.REMOVE})
+    @JoinColumn(name = "chat_room_id", nullable = false, foreignKey = @ForeignKey(name = "fk_read_message_log_chat_room"))
+    private ChatRoom chatRoom;
+
+    @OneToOne(fetch = FetchType.LAZY, cascade = {CascadeType.REMOVE})
+    @JoinColumn(name = "reader_id", nullable = false, foreignKey = @ForeignKey(name = "fk_read_message_log_reader"))
+    private User reader;
+
+    private Long lastReadMessageId = 0L;
+
+    public ReadMessageLog(final ChatRoom chatRoom, final User reader) {
+        this.chatRoom = chatRoom;
+        this.reader = reader;
+    }
+
+    public void updateLastReadMessage(final Long lastReadMessageId) {
+        this.lastReadMessageId = lastReadMessageId;
+    }
+}
diff --git a/backend/ddang/src/main/java/com/ddang/ddang/chat/domain/dto/ChatRoomAndMessageAndImageDto.java b/backend/ddang/src/main/java/com/ddang/ddang/chat/domain/dto/ChatRoomAndMessageAndImageDto.java
index 2e7e6ea6b..b31168c91 100644
--- a/backend/ddang/src/main/java/com/ddang/ddang/chat/domain/dto/ChatRoomAndMessageAndImageDto.java
+++ b/backend/ddang/src/main/java/com/ddang/ddang/chat/domain/dto/ChatRoomAndMessageAndImageDto.java
@@ -4,5 +4,10 @@
 import com.ddang.ddang.chat.domain.Message;
 import com.ddang.ddang.image.domain.AuctionImage;
 
-public record ChatRoomAndMessageAndImageDto(ChatRoom chatRoom, Message message, AuctionImage thumbnailImage) {
+public record ChatRoomAndMessageAndImageDto(
+        ChatRoom chatRoom,
+        Message message,
+        AuctionImage thumbnailImage,
+        Long unreadMessageCount
+) {
 }
diff --git a/backend/ddang/src/main/java/com/ddang/ddang/chat/domain/repository/ReadMessageLogRepository.java b/backend/ddang/src/main/java/com/ddang/ddang/chat/domain/repository/ReadMessageLogRepository.java
new file mode 100644
index 000000000..0da187e3a
--- /dev/null
+++ b/backend/ddang/src/main/java/com/ddang/ddang/chat/domain/repository/ReadMessageLogRepository.java
@@ -0,0 +1,13 @@
+package com.ddang.ddang.chat.domain.repository;
+
+import com.ddang.ddang.chat.domain.ReadMessageLog;
+
+import java.util.List;
+import java.util.Optional;
+
+public interface ReadMessageLogRepository {
+
+    Optional<ReadMessageLog> findBy(final Long readerId, final Long chatRoomId);
+
+    List<ReadMessageLog> saveAll(List<ReadMessageLog> readMessageLogs);
+}
diff --git a/backend/ddang/src/main/java/com/ddang/ddang/chat/infrastructure/persistence/JpaReadMessageLogRepository.java b/backend/ddang/src/main/java/com/ddang/ddang/chat/infrastructure/persistence/JpaReadMessageLogRepository.java
new file mode 100644
index 000000000..8ceceeb93
--- /dev/null
+++ b/backend/ddang/src/main/java/com/ddang/ddang/chat/infrastructure/persistence/JpaReadMessageLogRepository.java
@@ -0,0 +1,17 @@
+package com.ddang.ddang.chat.infrastructure.persistence;
+
+import com.ddang.ddang.chat.domain.ReadMessageLog;
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Query;
+
+import java.util.Optional;
+
+public interface JpaReadMessageLogRepository extends JpaRepository<ReadMessageLog, Long> {
+
+    @Query("""
+        SELECT rml
+        FROM ReadMessageLog rml 
+        WHERE rml.chatRoom.id = :chatRoomId AND rml.reader.id = :readerId
+    """)
+    Optional<ReadMessageLog> findLastReadMessageByUserIdAndChatRoomId(final Long readerId, final Long chatRoomId);
+}
diff --git a/backend/ddang/src/main/java/com/ddang/ddang/chat/infrastructure/persistence/QuerydslChatRoomAndMessageAndImageRepository.java b/backend/ddang/src/main/java/com/ddang/ddang/chat/infrastructure/persistence/QuerydslChatRoomAndMessageAndImageRepository.java
index 07e7bc5f7..26734527e 100644
--- a/backend/ddang/src/main/java/com/ddang/ddang/chat/infrastructure/persistence/QuerydslChatRoomAndMessageAndImageRepository.java
+++ b/backend/ddang/src/main/java/com/ddang/ddang/chat/infrastructure/persistence/QuerydslChatRoomAndMessageAndImageRepository.java
@@ -5,6 +5,7 @@
 import com.ddang.ddang.chat.infrastructure.persistence.dto.QChatRoomAndMessageAndImageQueryProjectionDto;
 import com.querydsl.core.types.dsl.BooleanExpression;
 import com.querydsl.jpa.JPAExpressions;
+import com.querydsl.jpa.JPQLQuery;
 import com.querydsl.jpa.impl.JPAQueryFactory;
 import lombok.RequiredArgsConstructor;
 import org.springframework.stereotype.Repository;
@@ -15,6 +16,7 @@
 import static com.ddang.ddang.auction.domain.QAuction.auction;
 import static com.ddang.ddang.chat.domain.QChatRoom.chatRoom;
 import static com.ddang.ddang.chat.domain.QMessage.message;
+import static com.ddang.ddang.chat.domain.QReadMessageLog.readMessageLog;
 import static com.ddang.ddang.image.domain.QAuctionImage.auctionImage;
 import static java.util.Comparator.comparing;
 
@@ -26,8 +28,12 @@ public class QuerydslChatRoomAndMessageAndImageRepository {
 
     public List<ChatRoomAndMessageAndImageDto> findAllChatRoomInfoByUserIdOrderByLastMessage(final Long userId) {
         final List<ChatRoomAndMessageAndImageQueryProjectionDto> unsortedDtos =
-                queryFactory.select(new QChatRoomAndMessageAndImageQueryProjectionDto(chatRoom, message, auctionImage))
-                            .from(chatRoom)
+                queryFactory.select(new QChatRoomAndMessageAndImageQueryProjectionDto(
+                                    chatRoom,
+                                    message,
+                                    auctionImage,
+                                    countUnreadMessages(userId)
+                            )).from(chatRoom)
                             .leftJoin(chatRoom.buyer).fetchJoin()
                             .leftJoin(chatRoom.auction, auction).fetchJoin()
                             .leftJoin(auction.seller).fetchJoin()
@@ -52,6 +58,21 @@ public List<ChatRoomAndMessageAndImageDto> findAllChatRoomInfoByUserIdOrderByLas
         return sortByLastMessageIdDesc(unsortedDtos);
     }
 
+    private static JPQLQuery<Long> countUnreadMessages(final Long userId) {
+        return JPAExpressions.select(message.count())
+                             .from(message)
+                             .where(
+                                     message.chatRoom.id.eq(chatRoom.id),
+                                     message.writer.id.ne(userId),
+                                     message.id.gt(
+                                             JPAExpressions
+                                                     .select(readMessageLog.lastReadMessageId)
+                                                     .from(readMessageLog)
+                                                     .where(readMessageLog.reader.id.eq(userId))
+                                     )
+                             );
+    }
+
     private List<ChatRoomAndMessageAndImageDto> sortByLastMessageIdDesc(
             final List<ChatRoomAndMessageAndImageQueryProjectionDto> unsortedDtos
     ) {
diff --git a/backend/ddang/src/main/java/com/ddang/ddang/chat/infrastructure/persistence/ReadMessageLogRepositoryImpl.java b/backend/ddang/src/main/java/com/ddang/ddang/chat/infrastructure/persistence/ReadMessageLogRepositoryImpl.java
new file mode 100644
index 000000000..dceecf3ed
--- /dev/null
+++ b/backend/ddang/src/main/java/com/ddang/ddang/chat/infrastructure/persistence/ReadMessageLogRepositoryImpl.java
@@ -0,0 +1,26 @@
+package com.ddang.ddang.chat.infrastructure.persistence;
+
+import com.ddang.ddang.chat.domain.ReadMessageLog;
+import com.ddang.ddang.chat.domain.repository.ReadMessageLogRepository;
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Repository;
+
+import java.util.List;
+import java.util.Optional;
+
+@Repository
+@RequiredArgsConstructor
+public class ReadMessageLogRepositoryImpl implements ReadMessageLogRepository {
+
+    private final JpaReadMessageLogRepository jpaReadMessageLogRepository;
+
+    @Override
+    public Optional<ReadMessageLog> findBy(final Long readerId, final Long chatRoomId) {
+        return jpaReadMessageLogRepository.findLastReadMessageByUserIdAndChatRoomId(readerId, chatRoomId);
+    }
+
+    @Override
+    public List<ReadMessageLog> saveAll(final List<ReadMessageLog> readMessageLogs) {
+        return jpaReadMessageLogRepository.saveAll(readMessageLogs);
+    }
+}
diff --git a/backend/ddang/src/main/java/com/ddang/ddang/chat/infrastructure/persistence/dto/ChatRoomAndMessageAndImageQueryProjectionDto.java b/backend/ddang/src/main/java/com/ddang/ddang/chat/infrastructure/persistence/dto/ChatRoomAndMessageAndImageQueryProjectionDto.java
index c4369d8f3..f4a2b49a3 100644
--- a/backend/ddang/src/main/java/com/ddang/ddang/chat/infrastructure/persistence/dto/ChatRoomAndMessageAndImageQueryProjectionDto.java
+++ b/backend/ddang/src/main/java/com/ddang/ddang/chat/infrastructure/persistence/dto/ChatRoomAndMessageAndImageQueryProjectionDto.java
@@ -6,7 +6,12 @@
 import com.ddang.ddang.image.domain.AuctionImage;
 import com.querydsl.core.annotations.QueryProjection;
 
-public record ChatRoomAndMessageAndImageQueryProjectionDto(ChatRoom chatRoom, Message message, AuctionImage auctionImage) {
+public record ChatRoomAndMessageAndImageQueryProjectionDto(
+        ChatRoom chatRoom,
+        Message message,
+        AuctionImage auctionImage,
+        Long unreadMessage
+) {
 
     @QueryProjection
     public ChatRoomAndMessageAndImageQueryProjectionDto {
@@ -16,7 +21,8 @@ public ChatRoomAndMessageAndImageDto toSortedDto() {
         return new ChatRoomAndMessageAndImageDto(
                 this.chatRoom,
                 this.message,
-                this.auctionImage
+                this.auctionImage,
+                this.unreadMessage
         );
     }
 }
diff --git a/backend/ddang/src/main/java/com/ddang/ddang/chat/presentation/dto/response/ReadChatRoomWithLastMessageResponse.java b/backend/ddang/src/main/java/com/ddang/ddang/chat/presentation/dto/response/ReadChatRoomWithLastMessageResponse.java
index 7aa99edc0..4c35179ea 100644
--- a/backend/ddang/src/main/java/com/ddang/ddang/chat/presentation/dto/response/ReadChatRoomWithLastMessageResponse.java
+++ b/backend/ddang/src/main/java/com/ddang/ddang/chat/presentation/dto/response/ReadChatRoomWithLastMessageResponse.java
@@ -7,6 +7,7 @@ public record ReadChatRoomWithLastMessageResponse(
         ReadChatPartnerResponse chatPartner,
         ReadAuctionInChatRoomResponse auction,
         ReadLastMessageResponse lastMessage,
+        Long unreadMessageCount,
         boolean isChatAvailable
 ) {
 
@@ -16,6 +17,7 @@ public static ReadChatRoomWithLastMessageResponse from(final ReadChatRoomWithLas
                 ReadChatPartnerResponse.from(dto.partnerDto()),
                 ReadAuctionInChatRoomResponse.from(dto.auctionDto()),
                 ReadLastMessageResponse.from(dto.lastMessageDto()),
+                dto.unreadMessageCount(),
                 dto.isChatAvailable()
         );
     }
diff --git a/backend/ddang/src/main/java/com/ddang/ddang/exception/GlobalExceptionHandler.java b/backend/ddang/src/main/java/com/ddang/ddang/exception/GlobalExceptionHandler.java
index e3c7b2ea0..5831faf10 100644
--- a/backend/ddang/src/main/java/com/ddang/ddang/exception/GlobalExceptionHandler.java
+++ b/backend/ddang/src/main/java/com/ddang/ddang/exception/GlobalExceptionHandler.java
@@ -16,6 +16,7 @@
 import com.ddang.ddang.chat.application.exception.InvalidAuctionToChatException;
 import com.ddang.ddang.chat.application.exception.InvalidUserToChat;
 import com.ddang.ddang.chat.application.exception.MessageNotFoundException;
+import com.ddang.ddang.chat.application.exception.ReadMessageLogNotFoundException;
 import com.ddang.ddang.chat.application.exception.UnableToChatException;
 import com.ddang.ddang.device.application.exception.DeviceTokenNotFoundException;
 import com.ddang.ddang.exception.dto.ExceptionResponse;
@@ -111,6 +112,14 @@ public ResponseEntity<ExceptionResponse> handleMessageNotFoundException(final Me
                              .body(new ExceptionResponse(ex.getMessage()));
     }
 
+    @ExceptionHandler(ReadMessageLogNotFoundException.class)
+    public ResponseEntity<ExceptionResponse> handleReadMessageNotFoundException(final ReadMessageLogNotFoundException ex) {
+        logger.warn(String.format(LOG_MESSAGE_FORMAT, ex.getClass().getSimpleName(), ex.getMessage()));
+
+        return ResponseEntity.status(HttpStatus.NOT_FOUND)
+                             .body(new ExceptionResponse(ex.getMessage()));
+    }
+
     @ExceptionHandler(UnableToChatException.class)
     public ResponseEntity<ExceptionResponse> handleUnableToChatException(final UnableToChatException ex) {
         logger.warn(String.format(LOG_MESSAGE_FORMAT, ex.getClass().getSimpleName(), ex.getMessage()));
diff --git a/backend/ddang/src/main/java/com/ddang/ddang/user/domain/repository/UserRepository.java b/backend/ddang/src/main/java/com/ddang/ddang/user/domain/repository/UserRepository.java
index 6f1b7fdfc..bf909cb60 100644
--- a/backend/ddang/src/main/java/com/ddang/ddang/user/domain/repository/UserRepository.java
+++ b/backend/ddang/src/main/java/com/ddang/ddang/user/domain/repository/UserRepository.java
@@ -10,8 +10,6 @@ public interface UserRepository {
 
     Optional<User> findById(final Long id);
 
-    boolean existsById(final Long id);
-
     Optional<User> findByOauthId(final String oauthId);
 
     boolean existsByIdAndDeletedIsTrue(final Long id);
diff --git a/backend/ddang/src/main/java/com/ddang/ddang/user/infrastructure/persistence/UserRepositoryImpl.java b/backend/ddang/src/main/java/com/ddang/ddang/user/infrastructure/persistence/UserRepositoryImpl.java
index 5a5e3fac6..1cff56988 100644
--- a/backend/ddang/src/main/java/com/ddang/ddang/user/infrastructure/persistence/UserRepositoryImpl.java
+++ b/backend/ddang/src/main/java/com/ddang/ddang/user/infrastructure/persistence/UserRepositoryImpl.java
@@ -23,11 +23,6 @@ public Optional<User> findById(final Long id) {
         return jpaUserRepository.findById(id);
     }
 
-    @Override
-    public boolean existsById(final Long id) {
-        return jpaUserRepository.existsById(id);
-    }
-
     @Override
     public Optional<User> findByOauthId(final String oauthId) {
         return jpaUserRepository.findByOauthId(oauthId);
diff --git a/backend/ddang/src/main/resources/db/migration/V21__create_read_message_log_tables.sql b/backend/ddang/src/main/resources/db/migration/V21__create_read_message_log_tables.sql
new file mode 100644
index 000000000..0cc6063d2
--- /dev/null
+++ b/backend/ddang/src/main/resources/db/migration/V21__create_read_message_log_tables.sql
@@ -0,0 +1,10 @@
+create table read_message_log (
+                                  id bigint not null auto_increment,
+                                  chat_room_id bigint,
+                                  reader_id bigint,
+                                  last_read_message_id bigint,
+                                  primary key (id)
+);
+
+alter table read_message_log add constraint fk_read_message_log_chat_room foreign key (chat_room_id) references chat_room (id);
+alter table read_message_log add constraint fk_read_message_reader foreign key (reader_id) references users (id);
diff --git a/backend/ddang/src/main/resources/static/docs/docs.html b/backend/ddang/src/main/resources/static/docs/docs.html
index 8bef9d493..4cf03fadb 100644
--- a/backend/ddang/src/main/resources/static/docs/docs.html
+++ b/backend/ddang/src/main/resources/static/docs/docs.html
@@ -516,9 +516,9 @@ <h1>땅땅땅 API 문서</h1>
 <li><a href="#_채팅방_신고_등록">채팅방 신고 등록</a></li>
 <li><a href="#_채팅방_신고_조회">채팅방 신고 조회</a></li>
 <li><a href="#_질문_신고_등록">질문 신고 등록</a></li>
-<li><a href="#_질문_신고_조회">질문 신고 조회</a></li>
+<li><a href="#_채팅방_신고_조회_2">채팅방 신고 조회</a></li>
 <li><a href="#_답변_신고_등록">답변 신고 등록</a></li>
-<li><a href="#_답변_신고_조회">답변 신고 조회</a></li>
+<li><a href="#_채팅방_신고_조회_3">채팅방 신고 조회</a></li>
 </ul>
 </li>
 <li><a href="#_디바이스_토큰_api">디바이스 토큰 API</a>
@@ -531,7 +531,7 @@ <h1>땅땅땅 API 문서</h1>
 <li><a href="#_사용자_평가_등록">사용자 평가 등록</a></li>
 <li><a href="#_지정한_평가_아이디에_해당하는_평가_조회">지정한 평가 아이디에 해당하는 평가 조회</a></li>
 <li><a href="#_지정한_사용자가_받은_평가_목록_조회">지정한 사용자가 받은 평가 목록 조회</a></li>
-<li><a href="#_사용자가_경매_거래_상대에게_작성한_평가를_조회한다">사용자가 경매 거래 상대에게 작성한 평가를 조회한다</a></li>
+<li><a href="#_사용자가_경매_거래_상대에게_작성한_평가를_조회한다">사용자가_경매_거래_상대에게_작성한_평가를_조회한다</a></li>
 </ul>
 </li>
 </ul>
@@ -914,6 +914,25 @@ <h4 id="_요청_5"><a class="link" href="#_요청_5">요청</a></h4>
 </div>
 </div>
 <table class="tableblock frame-all grid-all stretch">
+<caption class="title">Table 2. /oauth2/withdrawal/{oauth2Type}</caption>
+<colgroup>
+<col style="width: 50%;">
+<col style="width: 50%;">
+</colgroup>
+<thead>
+<tr>
+<th class="tableblock halign-left valign-top">Parameter</th>
+<th class="tableblock halign-left valign-top">Description</th>
+</tr>
+</thead>
+<tbody>
+<tr>
+<td class="tableblock halign-left valign-top"><p class="tableblock"><code>oauth2Type</code></p></td>
+<td class="tableblock halign-left valign-top"><p class="tableblock">소셜 로그인을 할 서비스 선택(kakao로 고정)</p></td>
+</tr>
+</tbody>
+</table>
+<table class="tableblock frame-all grid-all stretch">
 <colgroup>
 <col style="width: 50%;">
 <col style="width: 50%;">
@@ -1275,7 +1294,7 @@ <h4 id="_요청_11"><a class="link" href="#_요청_11">요청</a></h4>
 </div>
 </div>
 <table class="tableblock frame-all grid-all stretch">
-<caption class="title">Table 2. /regions/{firstId}</caption>
+<caption class="title">Table 3. /regions/{firstId}</caption>
 <colgroup>
 <col style="width: 50%;">
 <col style="width: 50%;">
@@ -1354,7 +1373,7 @@ <h4 id="_요청_12"><a class="link" href="#_요청_12">요청</a></h4>
 </div>
 </div>
 <table class="tableblock frame-all grid-all stretch">
-<caption class="title">Table 3. /regions/{firstId}/{secondId}</caption>
+<caption class="title">Table 4. /regions/{firstId}/{secondId}</caption>
 <colgroup>
 <col style="width: 50%;">
 <col style="width: 50%;">
@@ -1450,7 +1469,7 @@ <h4 id="_요청_13"><a class="link" href="#_요청_13">요청</a></h4>
 Content-Disposition: form-data; name=request; filename=request
 Content-Type: application/json
 
-{"title":"제목","description":"내용","bidUnit":1000,"startPrice":1000,"closingTime":"2023-10-22T15:18:31.556019","subCategoryId":2,"thirdRegionIds":[3]}
+{"title":"제목","description":"내용","bidUnit":1000,"startPrice":1000,"closingTime":"2023-11-03T16:59:34.062594","subCategoryId":2,"thirdRegionIds":[3]}
 --6o2knFse3p53ty9dmcQvWAIx1zInP11uCfbm--</code></pre>
 </div>
 </div>
@@ -1999,7 +2018,7 @@ <h4 id="_요청_17"><a class="link" href="#_요청_17">요청</a></h4>
 </div>
 </div>
 <table class="tableblock frame-all grid-all stretch">
-<caption class="title">Table 4. /auctions/{auctionId}</caption>
+<caption class="title">Table 5. /auctions/{auctionId}</caption>
 <colgroup>
 <col style="width: 50%;">
 <col style="width: 50%;">
@@ -2057,8 +2076,8 @@ <h4 id="_응답_17"><a class="link" href="#_응답_17">응답</a></h4>
     "lastBidPrice" : null,
     "status" : "UNBIDDEN",
     "bidUnit" : 1000,
-    "registerTime" : "2023-10-19T15:18:31",
-    "closingTime" : "2023-10-19T15:18:31",
+    "registerTime" : "2023-10-31T16:59:34",
+    "closingTime" : "2023-10-31T16:59:34",
     "directRegions" : [ {
       "first" : "서울특별시",
       "second" : "강서구",
@@ -2251,7 +2270,7 @@ <h4 id="_요청_18"><a class="link" href="#_요청_18">요청</a></h4>
 </div>
 </div>
 <table class="tableblock frame-all grid-all stretch">
-<caption class="title">Table 5. /auctions/{auctionId}</caption>
+<caption class="title">Table 6. /auctions/{auctionId}</caption>
 <colgroup>
 <col style="width: 50%;">
 <col style="width: 50%;">
@@ -2402,7 +2421,7 @@ <h4 id="_요청_20"><a class="link" href="#_요청_20">요청</a></h4>
 </tbody>
 </table>
 <table class="tableblock frame-all grid-all stretch">
-<caption class="title">Table 6. /questions/{questionId}</caption>
+<caption class="title">Table 7. /questions/{questionId}</caption>
 <colgroup>
 <col style="width: 50%;">
 <col style="width: 50%;">
@@ -2530,7 +2549,7 @@ <h4 id="_요청_22"><a class="link" href="#_요청_22">요청</a></h4>
 </tbody>
 </table>
 <table class="tableblock frame-all grid-all stretch">
-<caption class="title">Table 7. /questions/answers/{answerId}</caption>
+<caption class="title">Table 8. /questions/answers/{answerId}</caption>
 <colgroup>
 <col style="width: 50%;">
 <col style="width: 50%;">
@@ -2586,7 +2605,7 @@ <h4 id="_응답_23"><a class="link" href="#_응답_23">응답</a></h4>
         "name" : "질문자",
         "image" : "http://localhost:8080/users/images/1"
       },
-      "createdTime" : "2023-10-19T15:18:31",
+      "createdTime" : "2023-10-31T16:59:34",
       "content" : "질문1",
       "isQuestioner" : false
     },
@@ -2597,7 +2616,7 @@ <h4 id="_응답_23"><a class="link" href="#_응답_23">응답</a></h4>
         "name" : "판매자",
         "image" : "http://localhost:8080/users/images/2"
       },
-      "createdTime" : "2023-10-19T15:18:31",
+      "createdTime" : "2023-10-31T16:59:34",
       "content" : "답변1"
     }
   }, {
@@ -2608,7 +2627,7 @@ <h4 id="_응답_23"><a class="link" href="#_응답_23">응답</a></h4>
         "name" : "질문자",
         "image" : "http://localhost:8080/users/images/1"
       },
-      "createdTime" : "2023-10-19T15:18:31",
+      "createdTime" : "2023-10-31T16:59:34",
       "content" : "질문2",
       "isQuestioner" : false
     },
@@ -2619,7 +2638,7 @@ <h4 id="_응답_23"><a class="link" href="#_응답_23">응답</a></h4>
         "name" : "판매자",
         "image" : "http://localhost:8080/users/images/2"
       },
-      "createdTime" : "2023-10-19T15:18:31",
+      "createdTime" : "2023-10-31T16:59:34",
       "content" : "답변1"
     }
   } ]
@@ -2816,7 +2835,7 @@ <h3 id="_입찰_조회"><a class="link" href="#_입찰_조회">입찰 조회</a>
 <h4 id="_요청_25"><a class="link" href="#_요청_25">요청</a></h4>
 <div class="listingblock">
 <div class="content">
-<pre class="highlightjs highlight nowrap"><code class="language-http hljs" data-lang="http">GET /bids/1 HTTP/1.1
+<pre class="highlightjs highlight nowrap"><code class="language-http hljs" data-lang="http">GET /bids/-999 HTTP/1.1
 Content-Type: application/json</code></pre>
 </div>
 </div>
@@ -2832,12 +2851,12 @@ <h4 id="_응답_25"><a class="link" href="#_응답_25">응답</a></h4>
   "name" : "사용자1",
   "profileImage" : "http://localhost:8080/users/images/1",
   "price" : 10000,
-  "bidTime" : "2023-10-19T15:18:36"
+  "bidTime" : "2023-10-31T16:59:40"
 }, {
   "name" : "사용자2",
   "profileImage" : "http://localhost:8080/users/images/2",
   "price" : 12000,
-  "bidTime" : "2023-10-19T15:18:36"
+  "bidTime" : "2023-10-31T16:59:40"
 } ]</code></pre>
 </div>
 </div>
@@ -3031,7 +3050,7 @@ <h4 id="_응답_27"><a class="link" href="#_응답_27">응답</a></h4>
     "price" : 10000
   },
   "lastMessage" : {
-    "createdAt" : "2023-10-19T15:18:38",
+    "createdAt" : "2023-10-31T16:59:45",
     "contents" : "메시지1"
   },
   "isChatAvailable" : true
@@ -3049,7 +3068,7 @@ <h4 id="_응답_27"><a class="link" href="#_응답_27">응답</a></h4>
     "price" : 20000
   },
   "lastMessage" : {
-    "createdAt" : "2023-10-19T15:18:38",
+    "createdAt" : "2023-10-31T16:59:45",
     "contents" : "메시지2"
   },
   "isChatAvailable" : true
@@ -3161,7 +3180,7 @@ <h4 id="_요청_28"><a class="link" href="#_요청_28">요청</a></h4>
 </div>
 </div>
 <table class="tableblock frame-all grid-all stretch">
-<caption class="title">Table 8. /chattings/{chatRoomId}</caption>
+<caption class="title">Table 9. /chattings/{chatRoomId}</caption>
 <colgroup>
 <col style="width: 50%;">
 <col style="width: 50%;">
@@ -3312,7 +3331,7 @@ <h4 id="_요청_29"><a class="link" href="#_요청_29">요청</a></h4>
 </div>
 </div>
 <table class="tableblock frame-all grid-all stretch">
-<caption class="title">Table 9. /chattings/{chatRoomId}/messages</caption>
+<caption class="title">Table 10. /chattings/{chatRoomId}/messages</caption>
 <colgroup>
 <col style="width: 50%;">
 <col style="width: 50%;">
@@ -3423,7 +3442,7 @@ <h4 id="_요청_30"><a class="link" href="#_요청_30">요청</a></h4>
 </div>
 </div>
 <table class="tableblock frame-all grid-all stretch">
-<caption class="title">Table 10. /chattings/{chatRoomId}/messages</caption>
+<caption class="title">Table 11. /chattings/{chatRoomId}/messages</caption>
 <colgroup>
 <col style="width: 50%;">
 <col style="width: 50%;">
@@ -3487,7 +3506,7 @@ <h4 id="_응답_30"><a class="link" href="#_응답_30">응답</a></h4>
 
 [ {
   "id" : 1,
-  "createdAt" : "2023-10-19T15:18:38",
+  "createdAt" : "2023-10-31T16:59:44",
   "isMyMessage" : true,
   "contents" : "메시지내용"
 } ]</code></pre>
@@ -3637,7 +3656,7 @@ <h4 id="_응답_32"><a class="link" href="#_응답_32">응답</a></h4>
       "id" : 2,
       "name" : "회원1"
     },
-    "createdTime" : "2023-10-19T15:18:45",
+    "createdTime" : "2023-10-31T16:59:54",
     "auction" : {
       "id" : 1,
       "title" : "제목"
@@ -3649,7 +3668,7 @@ <h4 id="_응답_32"><a class="link" href="#_응답_32">응답</a></h4>
       "id" : 3,
       "name" : "회원2"
     },
-    "createdTime" : "2023-10-19T15:18:45",
+    "createdTime" : "2023-10-31T16:59:54",
     "auction" : {
       "id" : 1,
       "title" : "제목"
@@ -3661,7 +3680,7 @@ <h4 id="_응답_32"><a class="link" href="#_응답_32">응답</a></h4>
       "id" : 4,
       "name" : "회원3"
     },
-    "createdTime" : "2023-10-19T15:18:45",
+    "createdTime" : "2023-10-31T16:59:54",
     "auction" : {
       "id" : 1,
       "title" : "제목"
@@ -3825,7 +3844,7 @@ <h4 id="_응답_34"><a class="link" href="#_응답_34">응답</a></h4>
       "id" : 2,
       "name" : "구매자1"
     },
-    "createdTime" : "2023-10-19T15:18:45",
+    "createdTime" : "2023-10-31T16:59:54",
     "chatRoom" : {
       "id" : 1
     },
@@ -3836,7 +3855,7 @@ <h4 id="_응답_34"><a class="link" href="#_응답_34">응답</a></h4>
       "id" : 3,
       "name" : "구매자2"
     },
-    "createdTime" : "2023-10-19T15:18:45",
+    "createdTime" : "2023-10-31T16:59:54",
     "chatRoom" : {
       "id" : 1
     },
@@ -3847,7 +3866,7 @@ <h4 id="_응답_34"><a class="link" href="#_응답_34">응답</a></h4>
       "id" : 3,
       "name" : "구매자2"
     },
-    "createdTime" : "2023-10-19T15:18:45",
+    "createdTime" : "2023-10-31T16:59:54",
     "chatRoom" : {
       "id" : 1
     },
@@ -3987,7 +4006,7 @@ <h4 id="_응답_35"><a class="link" href="#_응답_35">응답</a></h4>
 </div>
 </div>
 <div class="sect2">
-<h3 id="_질문_신고_조회"><a class="link" href="#_질문_신고_조회">질문 신고 조회</a></h3>
+<h3 id="_채팅방_신고_조회_2"><a class="link" href="#_채팅방_신고_조회_2">채팅방 신고 조회</a></h3>
 <div class="sect3">
 <h4 id="_요청_36"><a class="link" href="#_요청_36">요청</a></h4>
 <div class="listingblock">
@@ -4011,7 +4030,7 @@ <h4 id="_응답_36"><a class="link" href="#_응답_36">응답</a></h4>
       "id" : 2,
       "name" : "구매자1"
     },
-    "createdTime" : "2023-10-19T15:18:46",
+    "createdTime" : "2023-10-31T16:59:55",
     "question" : {
       "id" : 1
     },
@@ -4022,7 +4041,7 @@ <h4 id="_응답_36"><a class="link" href="#_응답_36">응답</a></h4>
       "id" : 2,
       "name" : "구매자1"
     },
-    "createdTime" : "2023-10-19T15:18:46",
+    "createdTime" : "2023-10-31T16:59:55",
     "question" : {
       "id" : 2
     },
@@ -4033,7 +4052,7 @@ <h4 id="_응답_36"><a class="link" href="#_응답_36">응답</a></h4>
       "id" : 2,
       "name" : "구매자1"
     },
-    "createdTime" : "2023-10-19T15:18:46",
+    "createdTime" : "2023-10-31T16:59:55",
     "question" : {
       "id" : 3
     },
@@ -4173,7 +4192,7 @@ <h4 id="_응답_37"><a class="link" href="#_응답_37">응답</a></h4>
 </div>
 </div>
 <div class="sect2">
-<h3 id="_답변_신고_조회"><a class="link" href="#_답변_신고_조회">답변 신고 조회</a></h3>
+<h3 id="_채팅방_신고_조회_3"><a class="link" href="#_채팅방_신고_조회_3">채팅방 신고 조회</a></h3>
 <div class="sect3">
 <h4 id="_요청_38"><a class="link" href="#_요청_38">요청</a></h4>
 <div class="listingblock">
@@ -4197,7 +4216,7 @@ <h4 id="_응답_38"><a class="link" href="#_응답_38">응답</a></h4>
       "id" : 2,
       "name" : "구매자1"
     },
-    "createdTime" : "2023-10-19T15:18:46",
+    "createdTime" : "2023-10-31T16:59:55",
     "answer" : {
       "id" : 1
     },
@@ -4208,7 +4227,7 @@ <h4 id="_응답_38"><a class="link" href="#_응답_38">응답</a></h4>
       "id" : 2,
       "name" : "구매자1"
     },
-    "createdTime" : "2023-10-19T15:18:46",
+    "createdTime" : "2023-10-31T16:59:55",
     "answer" : {
       "id" : 2
     },
@@ -4219,7 +4238,7 @@ <h4 id="_응답_38"><a class="link" href="#_응답_38">응답</a></h4>
       "id" : 2,
       "name" : "구매자1"
     },
-    "createdTime" : "2023-10-19T15:18:46",
+    "createdTime" : "2023-10-31T16:59:55",
     "answer" : {
       "id" : 3
     },
@@ -4449,7 +4468,7 @@ <h4 id="_요청_41"><a class="link" href="#_요청_41">요청</a></h4>
 </div>
 </div>
 <table class="tableblock frame-all grid-all stretch">
-<caption class="title">Table 11. /reviews/{reviewId}</caption>
+<caption class="title">Table 12. /reviews/{reviewId}</caption>
 <colgroup>
 <col style="width: 50%;">
 <col style="width: 50%;">
@@ -4520,7 +4539,7 @@ <h4 id="_요청_42"><a class="link" href="#_요청_42">요청</a></h4>
 </div>
 </div>
 <table class="tableblock frame-all grid-all stretch">
-<caption class="title">Table 12. /reviews/users/{userId}</caption>
+<caption class="title">Table 13. /reviews/users/{userId}</caption>
 <colgroup>
 <col style="width: 50%;">
 <col style="width: 50%;">
@@ -4555,7 +4574,7 @@ <h4 id="_응답_42"><a class="link" href="#_응답_42">응답</a></h4>
   },
   "content" : "친절하다.",
   "score" : 5.0,
-  "createdTime" : "2023-10-19T15:18:46"
+  "createdTime" : "2023-10-31T16:59:56"
 }, {
   "id" : 2,
   "writer" : {
@@ -4565,7 +4584,7 @@ <h4 id="_응답_42"><a class="link" href="#_응답_42">응답</a></h4>
   },
   "content" : "친절하다.",
   "score" : 5.0,
-  "createdTime" : "2023-10-19T15:18:46"
+  "createdTime" : "2023-10-31T16:59:56"
 } ]</code></pre>
 </div>
 </div>
@@ -4628,7 +4647,7 @@ <h4 id="_응답_42"><a class="link" href="#_응답_42">응답</a></h4>
 </div>
 </div>
 <div class="sect2">
-<h3 id="_사용자가_경매_거래_상대에게_작성한_평가를_조회한다"><a class="link" href="#_사용자가_경매_거래_상대에게_작성한_평가를_조회한다">사용자가 경매 거래 상대에게 작성한 평가를 조회한다</a></h3>
+<h3 id="_사용자가_경매_거래_상대에게_작성한_평가를_조회한다"><a class="link" href="#_사용자가_경매_거래_상대에게_작성한_평가를_조회한다">사용자가_경매_거래_상대에게_작성한_평가를_조회한다</a></h3>
 <div class="sect3">
 <h4 id="_요청_43"><a class="link" href="#_요청_43">요청</a></h4>
 <div class="listingblock">
@@ -4639,7 +4658,7 @@ <h4 id="_요청_43"><a class="link" href="#_요청_43">요청</a></h4>
 </div>
 </div>
 <table class="tableblock frame-all grid-all stretch">
-<caption class="title">Table 13. /auctions/{auctionId}/reviews</caption>
+<caption class="title">Table 14. /auctions/{auctionId}/reviews</caption>
 <colgroup>
 <col style="width: 50%;">
 <col style="width: 50%;">
@@ -4723,7 +4742,7 @@ <h4 id="_응답_43"><a class="link" href="#_응답_43">응답</a></h4>
 <div id="footer">
 <div id="footer-text">
 Version 0.0.1-SNAPSHOT<br>
-Last updated 2023-10-19 15:16:35 +0900
+Last updated 2023-10-23 21:24:31 +0900
 </div>
 </div>
 <script src="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/9.18.3/highlight.min.js"></script>
@@ -4734,4 +4753,4 @@ <h4 id="_응답_43"><a class="link" href="#_응답_43">응답</a></h4>
 }
 </script>
 </body>
-</html>
\ No newline at end of file
+</html>
diff --git a/backend/ddang/src/test/java/com/ddang/ddang/chat/application/ChatRoomServiceTest.java b/backend/ddang/src/test/java/com/ddang/ddang/chat/application/ChatRoomServiceTest.java
index de0cccb21..eeb42b1fb 100644
--- a/backend/ddang/src/test/java/com/ddang/ddang/chat/application/ChatRoomServiceTest.java
+++ b/backend/ddang/src/test/java/com/ddang/ddang/chat/application/ChatRoomServiceTest.java
@@ -5,10 +5,13 @@
 import com.ddang.ddang.auction.domain.exception.WinnerNotFoundException;
 import com.ddang.ddang.chat.application.dto.ReadChatRoomWithLastMessageDto;
 import com.ddang.ddang.chat.application.dto.ReadParticipatingChatRoomDto;
+import com.ddang.ddang.chat.application.event.CreateReadMessageLogEvent;
 import com.ddang.ddang.chat.application.exception.ChatRoomNotFoundException;
 import com.ddang.ddang.chat.application.exception.InvalidAuctionToChatException;
 import com.ddang.ddang.chat.application.exception.InvalidUserToChat;
 import com.ddang.ddang.chat.application.fixture.ChatRoomServiceFixture;
+import com.ddang.ddang.chat.domain.repository.MessageRepository;
+import com.ddang.ddang.chat.domain.repository.ReadMessageLogRepository;
 import com.ddang.ddang.configuration.IsolateDatabase;
 import com.ddang.ddang.user.application.exception.UserNotFoundException;
 import org.assertj.core.api.SoftAssertions;
@@ -16,6 +19,8 @@
 import org.junit.jupiter.api.DisplayNameGenerator;
 import org.junit.jupiter.api.Test;
 import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.test.context.event.ApplicationEvents;
+import org.springframework.test.context.event.RecordApplicationEvents;
 
 import java.util.List;
 
@@ -23,6 +28,7 @@
 import static org.assertj.core.api.Assertions.assertThatThrownBy;
 
 @IsolateDatabase
+@RecordApplicationEvents
 @DisplayNameGeneration(DisplayNameGenerator.ReplaceUnderscores.class)
 @SuppressWarnings("NonAsciiCharacters")
 class ChatRoomServiceTest extends ChatRoomServiceFixture {
@@ -30,6 +36,15 @@ class ChatRoomServiceTest extends ChatRoomServiceFixture {
     @Autowired
     ChatRoomService chatRoomService;
 
+    @Autowired
+    ReadMessageLogRepository readMessageLogRepository;
+
+    @Autowired
+    MessageRepository messageRepository;
+
+    @Autowired
+    ApplicationEvents events;
+
     @Test
     void 채팅방을_생성한다() {
         // when
@@ -39,6 +54,16 @@ class ChatRoomServiceTest extends ChatRoomServiceFixture {
         assertThat(actual).isPositive();
     }
 
+    @Test
+    void 채팅방_생성시_메시지_로그_생성_이벤트가_호출된다() {
+        // when
+        chatRoomService.create(구매자.getId(), 채팅방_생성을_위한_DTO);
+        final long actual = events.stream(CreateReadMessageLogEvent.class).count();
+
+        // then
+        assertThat(actual).isEqualTo(1);
+    }
+
     @Test
     void 채팅방_생성시_요청한_사용자_정보를_찾을_수_없다면_예외가_발생한다() {
         // when & then
@@ -96,8 +121,21 @@ class ChatRoomServiceTest extends ChatRoomServiceFixture {
         // then
         SoftAssertions.assertSoftly(softAssertions -> {
             softAssertions.assertThat(actual).hasSize(2);
-            softAssertions.assertThat(actual.get(0)).isEqualTo(엔초_채팅_목록의_제이미_엔초_채팅방_정보);
-            softAssertions.assertThat(actual.get(1)).isEqualTo(엔초_채팅_목록의_엔초_지토_채팅방_정보);
+            softAssertions.assertThat(actual.get(0).id()).isEqualTo(엔초_채팅_목록의_제이미_엔초_채팅방_정보.id());
+            softAssertions.assertThat(actual.get(0).auctionDto()).isEqualTo(엔초_채팅_목록의_제이미_엔초_채팅방_정보.auctionDto());
+            softAssertions.assertThat(actual.get(0).partnerDto()).isEqualTo(엔초_채팅_목록의_제이미_엔초_채팅방_정보.partnerDto());
+            softAssertions.assertThat(actual.get(0).lastMessageDto())
+                          .isEqualTo(엔초_채팅_목록의_제이미_엔초_채팅방_정보.lastMessageDto());
+            softAssertions.assertThat(actual.get(0).isChatAvailable())
+                          .isEqualTo(엔초_채팅_목록의_제이미_엔초_채팅방_정보.isChatAvailable());
+
+            softAssertions.assertThat(actual.get(1).id()).isEqualTo(엔초_채팅_목록의_엔초_지토_채팅방_정보.id());
+            softAssertions.assertThat(actual.get(1).auctionDto()).isEqualTo(엔초_채팅_목록의_엔초_지토_채팅방_정보.auctionDto());
+            softAssertions.assertThat(actual.get(1).partnerDto()).isEqualTo(엔초_채팅_목록의_엔초_지토_채팅방_정보.partnerDto());
+            softAssertions.assertThat(actual.get(1).lastMessageDto())
+                          .isEqualTo(엔초_채팅_목록의_엔초_지토_채팅방_정보.lastMessageDto());
+            softAssertions.assertThat(actual.get(1).isChatAvailable())
+                          .isEqualTo(엔초_채팅_목록의_엔초_지토_채팅방_정보.isChatAvailable());
         });
     }
 
diff --git a/backend/ddang/src/test/java/com/ddang/ddang/chat/application/LastReadMessageLogEventListenerTest.java b/backend/ddang/src/test/java/com/ddang/ddang/chat/application/LastReadMessageLogEventListenerTest.java
new file mode 100644
index 000000000..5e0041468
--- /dev/null
+++ b/backend/ddang/src/test/java/com/ddang/ddang/chat/application/LastReadMessageLogEventListenerTest.java
@@ -0,0 +1,76 @@
+package com.ddang.ddang.chat.application;
+
+import com.ddang.ddang.chat.application.exception.ReadMessageLogNotFoundException;
+import com.ddang.ddang.chat.application.fixture.LastReadMessageLogEventListenerFixture;
+import com.ddang.ddang.configuration.IsolateDatabase;
+import org.junit.jupiter.api.DisplayNameGeneration;
+import org.junit.jupiter.api.DisplayNameGenerator;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.mock.mockito.MockBean;
+import org.springframework.test.context.event.ApplicationEvents;
+import org.springframework.test.context.event.RecordApplicationEvents;
+
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.BDDMockito.willDoNothing;
+import static org.mockito.BDDMockito.willThrow;
+import static org.mockito.Mockito.verify;
+
+@IsolateDatabase
+@RecordApplicationEvents
+@DisplayNameGeneration(DisplayNameGenerator.ReplaceUnderscores.class)
+@SuppressWarnings("NonAsciiCharacters")
+class LastReadMessageLogEventListenerTest extends LastReadMessageLogEventListenerFixture {
+
+    @Autowired
+    ApplicationEvents events;
+
+    @Autowired
+    LastReadMessageLogEventListener lastReadMessageLogEventListener;
+
+    @MockBean
+    LastReadMessageLogService lastReadMessageLogService;
+
+    @Test
+    void 이벤트가_호출되면_메시지_로그를_저장한다() {
+        // given
+        willDoNothing().given(lastReadMessageLogService).create(any());
+
+        // when
+        lastReadMessageLogEventListener.create(생성용_메시지_조회_로그);
+
+        // then
+        verify(lastReadMessageLogService).create(any());
+    }
+
+    @Test
+    void 메시지_로그_저장에_실패한_경우_예외가_발생하지_않는다() {
+        // given
+        willThrow(IllegalArgumentException.class).given(lastReadMessageLogService).create(any());
+
+        // when & then
+        assertDoesNotThrow(() -> lastReadMessageLogEventListener.create(생성용_메시지_조회_로그));
+    }
+
+    @Test
+    void 이벤트가_호출되면_메시지_로그를_업데이트한다() {
+        // given
+        willDoNothing().given(lastReadMessageLogService).update(any());
+
+        // when
+        lastReadMessageLogEventListener.update(업데이트용_메시지_조회_로그);
+
+        // then
+        verify(lastReadMessageLogService).update(any());
+    }
+
+    @Test
+    void 메시지_로그_업데이트에_실패한_경우_예외가_발생하지_않는다() {
+        // given
+        willThrow(ReadMessageLogNotFoundException.class).given(lastReadMessageLogService).update(any());
+
+        // when & then
+        assertDoesNotThrow(() -> lastReadMessageLogEventListener.update(업데이트용_메시지_조회_로그));
+    }
+}
diff --git a/backend/ddang/src/test/java/com/ddang/ddang/chat/application/LastReadMessageLogServiceTest.java b/backend/ddang/src/test/java/com/ddang/ddang/chat/application/LastReadMessageLogServiceTest.java
new file mode 100644
index 000000000..5512fabe3
--- /dev/null
+++ b/backend/ddang/src/test/java/com/ddang/ddang/chat/application/LastReadMessageLogServiceTest.java
@@ -0,0 +1,75 @@
+package com.ddang.ddang.chat.application;
+
+import com.ddang.ddang.chat.application.exception.ReadMessageLogNotFoundException;
+import com.ddang.ddang.chat.application.fixture.LastReadMessageLogServiceFixture;
+import com.ddang.ddang.chat.domain.ReadMessageLog;
+import com.ddang.ddang.chat.domain.repository.ReadMessageLogRepository;
+import com.ddang.ddang.configuration.IsolateDatabase;
+import org.assertj.core.api.SoftAssertions;
+import org.junit.jupiter.api.DisplayNameGeneration;
+import org.junit.jupiter.api.DisplayNameGenerator;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.test.context.event.RecordApplicationEvents;
+
+import java.util.Optional;
+
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+
+@IsolateDatabase
+@RecordApplicationEvents
+@DisplayNameGeneration(DisplayNameGenerator.ReplaceUnderscores.class)
+@SuppressWarnings("NonAsciiCharacters")
+class LastReadMessageLogServiceTest extends LastReadMessageLogServiceFixture {
+
+    @Autowired
+    LastReadMessageLogService lastReadMessageLogService;
+
+    @Autowired
+    ReadMessageLogRepository readMessageLogRepository;
+
+    @Test
+    void 메시지_로그를_생성한다() {
+        // given & when
+        lastReadMessageLogService.create(메시지_로그_생성용_이벤트);
+        final Optional<ReadMessageLog> actual_판매자 = readMessageLogRepository.findBy(메시지_로그_생성용_발신자_겸_판매자.getId(), 메시지_로그_생성용_채팅방.getId());
+        final Optional<ReadMessageLog> actual_구매자 = readMessageLogRepository.findBy(메시지_로그_생성용_입찰자_구매자.getId(), 메시지_로그_생성용_채팅방.getId());
+
+        // then
+        SoftAssertions.assertSoftly(softAssertions -> {
+            softAssertions.assertThat(actual_판매자).isPresent();
+            softAssertions.assertThat(actual_구매자).isPresent();
+        });
+    }
+
+    @Test
+    void 메시지_로그를_업데이트한다() {
+        // given & when
+        lastReadMessageLogService.update(메시지_로그_업데이트용_이벤트);
+
+        final Optional<ReadMessageLog> actual_발신자 = readMessageLogRepository.findBy(
+                메시지_로그_업데이트용_발신자_겸_판매자.getId(),
+                메시지_로그_업데이트용_채팅방.getId()
+        );
+        final Optional<ReadMessageLog> actual_입찰자 = readMessageLogRepository.findBy(
+                메시지_로그_업데이트용_입찰자.getId(),
+                메시지_로그_업데이트용_채팅방.getId()
+        );
+
+        // then
+        SoftAssertions.assertSoftly(softAssertions -> {
+            softAssertions.assertThat(actual_발신자).isPresent();
+            softAssertions.assertThat(actual_발신자.get().getLastReadMessageId())
+                          .isEqualTo(메시지_로그_업데이트용_마지막_조회_메시지.getId());
+            softAssertions.assertThat(actual_입찰자.get().getLastReadMessageId())
+                          .isNotEqualTo(메시지_로그_업데이트용_마지막_조회_메시지.getId());
+        });
+    }
+
+    @Test
+    void 메시지_로그_업데이트시_메시지_조회_로그가_존재하지_않으면_예외가_발생한다() {
+        // when & then
+        assertThatThrownBy(() -> lastReadMessageLogService.update(유효하지_않는_메시지_조회_로그))
+                .isInstanceOf(ReadMessageLogNotFoundException.class);
+    }
+}
diff --git a/backend/ddang/src/test/java/com/ddang/ddang/chat/application/MessageServiceTest.java b/backend/ddang/src/test/java/com/ddang/ddang/chat/application/MessageServiceTest.java
index a65cadb92..7794679c5 100644
--- a/backend/ddang/src/test/java/com/ddang/ddang/chat/application/MessageServiceTest.java
+++ b/backend/ddang/src/test/java/com/ddang/ddang/chat/application/MessageServiceTest.java
@@ -2,9 +2,11 @@
 
 import com.ddang.ddang.chat.application.dto.ReadMessageDto;
 import com.ddang.ddang.chat.application.event.MessageNotificationEvent;
+import com.ddang.ddang.chat.application.event.UpdateReadMessageLogEvent;
 import com.ddang.ddang.chat.application.exception.ChatRoomNotFoundException;
 import com.ddang.ddang.chat.application.exception.MessageNotFoundException;
 import com.ddang.ddang.chat.application.fixture.MessageServiceFixture;
+import com.ddang.ddang.chat.domain.repository.ReadMessageLogRepository;
 import com.ddang.ddang.configuration.IsolateDatabase;
 import com.ddang.ddang.notification.application.NotificationService;
 import com.ddang.ddang.notification.application.dto.CreateNotificationDto;
@@ -25,6 +27,7 @@
 import static org.assertj.core.api.Assertions.assertThatThrownBy;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.BDDMockito.given;
+import static org.mockito.BDDMockito.willDoNothing;
 
 @IsolateDatabase
 @RecordApplicationEvents
@@ -35,9 +38,15 @@ class MessageServiceTest extends MessageServiceFixture {
     @Autowired
     MessageService messageService;
 
+    @Autowired
+    ReadMessageLogRepository readMessageLogRepository;
+
     @MockBean
     NotificationService notificationService;
 
+    @MockBean
+    LastReadMessageLogService lastReadMessageLogService;
+
     @Autowired
     ApplicationEvents events;
 
@@ -101,6 +110,9 @@ class MessageServiceTest extends MessageServiceFixture {
 
     @Test
     void 마지막_조회_메시지가_없는_경우_모든_메시지를_조회한다() {
+        // given
+        willDoNothing().given(lastReadMessageLogService).update(any());
+
         // when
         final List<ReadMessageDto> actual = messageService.readAllByLastMessageId(마지막_조회_메시지_아이디가_없는_메시지_조회용_request);
 
@@ -110,6 +122,9 @@ class MessageServiceTest extends MessageServiceFixture {
 
     @Test
     void 첫_번째_메시지_이후에_생성된_모든_메시지를_조회한다() {
+        // given
+        willDoNothing().given(lastReadMessageLogService).update(any());
+
         // when
         final List<ReadMessageDto> actual = messageService.readAllByLastMessageId(두_번째_메시지부터_모든_메시지_조회용_request);
 
@@ -126,6 +141,16 @@ class MessageServiceTest extends MessageServiceFixture {
         assertThat(readMessageDtos).isEmpty();
     }
 
+    @Test
+    void 메시지를_조회할_경우_마지막으로_읽은_메시지_업데이트_이벤트를_호출한다() {
+        // when
+        messageService.readAllByLastMessageId(조회한_마지막_메시지가_5인_메시지_조회용_request);
+        final long actual = events.stream(UpdateReadMessageLogEvent.class).count();
+
+        // then
+        assertThat(actual).isEqualTo(1);
+    }
+
     @Test
     void 잘못된_사용자가_메시지를_조회할_경우_예외가_발생한다() {
         // when & then
diff --git a/backend/ddang/src/test/java/com/ddang/ddang/chat/application/fixture/ChatRoomServiceFixture.java b/backend/ddang/src/test/java/com/ddang/ddang/chat/application/fixture/ChatRoomServiceFixture.java
index 234913411..e53afed2b 100644
--- a/backend/ddang/src/test/java/com/ddang/ddang/chat/application/fixture/ChatRoomServiceFixture.java
+++ b/backend/ddang/src/test/java/com/ddang/ddang/chat/application/fixture/ChatRoomServiceFixture.java
@@ -59,6 +59,8 @@ public class ChatRoomServiceFixture {
     protected User 엔초;
     protected User 제이미;
     protected User 지토;
+    protected User 채팅방을_생성하는_메리;
+    protected User 메리_경매_낙찰자_지토;
     protected User 경매에_참여한_적_없는_사용자;
     protected Auction 채팅방이_없는_경매;
     protected Auction 판매자_엔초_구매자_지토_경매;
@@ -78,6 +80,7 @@ public class ChatRoomServiceFixture {
     protected CreateChatRoomDto 경매가_진행중이라서_채팅방을_생성할_수_없는_DTO;
     protected CreateChatRoomDto 낙찰자가_없어서_채팅방을_생성할_수_없는_DTO;
     protected CreateChatRoomDto 엔초_지토_채팅방_생성을_위한_DTO;
+    protected CreateChatRoomDto 메리가_생성하려는_채팅방;
     protected ReadParticipatingChatRoomDto 엔초가_조회한_엔초_지토_채팅방_정보_조회_결과;
     protected ReadChatRoomDto 엔초_지토_채팅방_정보_및_참여_가능;
     protected ReadChatRoomDto 엔초_지토_채팅방_정보_및_참여_불가능;
@@ -120,32 +123,46 @@ void setUp() {
                  .name("엔초")
                  .profileImage(프로필_이미지)
                  .reliability(new Reliability(4.7d))
-                 .oauthId("12346")
+                 .oauthId("12347")
                  .build();
         제이미 = User.builder()
                   .name("제이미")
                   .profileImage(프로필_이미지)
                   .reliability(new Reliability(4.7d))
-                  .oauthId("12347")
+                  .oauthId("12348")
                   .build();
         지토 = User.builder()
                  .name("지토")
                  .profileImage(프로필_이미지)
                  .reliability(new Reliability(4.7d))
-                 .oauthId("12348")
+                 .oauthId("12349")
                  .build();
         경매에_참여한_적_없는_사용자 = User.builder()
                                .name("외부인")
                                .profileImage(프로필_이미지)
                                .reliability(new Reliability(4.7d))
-                               .oauthId("12349")
+                               .oauthId("12340")
                                .build();
+        채팅방을_생성하는_메리 = User.builder()
+                           .name("채팅방을_생성하는_메리")
+                           .profileImage(프로필_이미지)
+                           .reliability(new Reliability(4.7d))
+                           .oauthId("09876")
+                           .build();
+        메리_경매_낙찰자_지토 = User.builder()
+                           .name("메리_경매_낙찰자_지토")
+                           .profileImage(프로필_이미지)
+                           .reliability(new Reliability(4.7d))
+                           .oauthId("10293")
+                           .build();
         userRepository.save(판매자);
         userRepository.save(구매자);
         userRepository.save(엔초);
         userRepository.save(제이미);
         userRepository.save(지토);
         userRepository.save(경매에_참여한_적_없는_사용자);
+        userRepository.save(채팅방을_생성하는_메리);
+        userRepository.save(메리_경매_낙찰자_지토);
 
         채팅방이_없는_경매 = Auction.builder()
                             .seller(판매자)
@@ -192,25 +209,39 @@ void setUp() {
                                                  .bidUnit(new BidUnit(1_000))
                                                  .closingTime(LocalDateTime.now())
                                                  .build();
+        final Auction 판매자_메리_구매자_지토_경매 = Auction.builder()
+                                                .seller(채팅방을_생성하는_메리)
+                                                .title("메리 맥북")
+                                                .description("메리 맥북 팔아요")
+                                                .subCategory(전자기기_서브_노트북_카테고리)
+                                                .startPrice(new Price(10_000))
+                                                .bidUnit(new BidUnit(1_000))
+                                                .closingTime(LocalDateTime.now())
+                                                .build();
         채팅방이_없는_경매.addAuctionImages(List.of(경매_대표_이미지, 대표_이미지가_아닌_경매_이미지));
         판매자_엔초_구매자_지토_경매.addAuctionImages(List.of(엔초의_경매_대표_이미지, 엔초의_대표_이미지가_아닌_경매_이미지));
         판매자_제이미_구매자_엔초_경매.addAuctionImages(List.of(제이미의_경매_대표_이미지, 제이미의_대표_이미지가_아닌_경매_이미지));
+        판매자_메리_구매자_지토_경매.addAuctionImages(List.of(경매_대표_이미지, 대표_이미지가_아닌_경매_이미지));
 
         auctionRepository.save(채팅방이_없는_경매);
         auctionRepository.save(종료되지_않은_경매);
         auctionRepository.save(낙찰자가_없는_경매);
         auctionRepository.save(판매자_엔초_구매자_지토_경매);
         auctionRepository.save(판매자_제이미_구매자_엔초_경매);
+        auctionRepository.save(판매자_메리_구매자_지토_경매);
 
         final Bid 채팅방_없는_경매_입찰 = new Bid(채팅방이_없는_경매, 구매자, new BidPrice(15_000));
         final Bid 지토가_엔초_경매에_입찰 = new Bid(판매자_엔초_구매자_지토_경매, 지토, new BidPrice(15_000));
         final Bid 엔초가_제이미_경매에_입찰 = new Bid(판매자_제이미_구매자_엔초_경매, 엔초, new BidPrice(15_000));
+        final Bid 지토가_메리_경매에_입찰 = new Bid(판매자_메리_구매자_지토_경매, 메리_경매_낙찰자_지토, new BidPrice(15_000));
         bidRepository.save(채팅방_없는_경매_입찰);
         bidRepository.save(지토가_엔초_경매에_입찰);
         bidRepository.save(엔초가_제이미_경매에_입찰);
+        bidRepository.save(지토가_메리_경매에_입찰);
         채팅방이_없는_경매.updateLastBid(채팅방_없는_경매_입찰);
         판매자_엔초_구매자_지토_경매.updateLastBid(지토가_엔초_경매에_입찰);
         판매자_제이미_구매자_엔초_경매.updateLastBid(엔초가_제이미_경매에_입찰);
+        판매자_메리_구매자_지토_경매.updateLastBid(지토가_메리_경매에_입찰);
 
         엔초_지토_채팅방 = new ChatRoom(판매자_엔초_구매자_지토_경매, 지토);
         제이미_엔초_채팅방 = new ChatRoom(판매자_제이미_구매자_엔초_경매, 엔초);
@@ -239,6 +270,7 @@ void setUp() {
         경매에_참여한_적_없는_사용자_정보 = new AuthenticationUserInfo(경매에_참여한_적_없는_사용자.getId());
         존재하지_않는_사용자_정보 = new AuthenticationUserInfo(존재하지_않는_사용자_아이디);
         채팅방_생성을_위한_DTO = new CreateChatRoomDto(채팅방이_없는_경매.getId());
+        메리가_생성하려는_채팅방 = new CreateChatRoomDto(판매자_메리_구매자_지토_경매.getId());
         경매_정보가_없어서_채팅방을_생성할_수_없는_DTO = new CreateChatRoomDto(존재하지_않는_경매_아이디);
         경매가_진행중이라서_채팅방을_생성할_수_없는_DTO = new CreateChatRoomDto(종료되지_않은_경매.getId());
         낙찰자가_없어서_채팅방을_생성할_수_없는_DTO = new CreateChatRoomDto(낙찰자가_없는_경매.getId());
@@ -253,6 +285,7 @@ void setUp() {
                 ReadAuctionInChatRoomDto.of(판매자_제이미_구매자_엔초_경매, 제이미의_경매_대표_이미지),
                 ReadUserInChatRoomDto.from(제이미),
                 ReadLastMessageDto.from(제이미가_엔초에게_2시에_보낸_쪽지),
+                1L,
                 true
         );
         엔초_채팅_목록의_엔초_지토_채팅방_정보 = new ReadChatRoomWithLastMessageDto(
@@ -260,6 +293,7 @@ void setUp() {
                 ReadAuctionInChatRoomDto.of(판매자_엔초_구매자_지토_경매, 엔초의_경매_대표_이미지),
                 ReadUserInChatRoomDto.from(지토),
                 ReadLastMessageDto.from(엔초가_지토에게_1시에_보낸_쪽지),
+                1L,
                 true
         );
     }
diff --git a/backend/ddang/src/test/java/com/ddang/ddang/chat/application/fixture/LastReadMessageLogEventListenerFixture.java b/backend/ddang/src/test/java/com/ddang/ddang/chat/application/fixture/LastReadMessageLogEventListenerFixture.java
new file mode 100644
index 000000000..dc0bd5c35
--- /dev/null
+++ b/backend/ddang/src/test/java/com/ddang/ddang/chat/application/fixture/LastReadMessageLogEventListenerFixture.java
@@ -0,0 +1,63 @@
+package com.ddang.ddang.chat.application.fixture;
+
+import com.ddang.ddang.auction.domain.Auction;
+import com.ddang.ddang.chat.application.event.CreateReadMessageLogEvent;
+import com.ddang.ddang.chat.application.event.UpdateReadMessageLogEvent;
+import com.ddang.ddang.chat.domain.ChatRoom;
+import com.ddang.ddang.chat.domain.Message;
+import com.ddang.ddang.image.domain.ProfileImage;
+import com.ddang.ddang.user.domain.Reliability;
+import com.ddang.ddang.user.domain.User;
+import org.junit.jupiter.api.BeforeEach;
+
+@SuppressWarnings("NonAsciiCharacters")
+public class LastReadMessageLogEventListenerFixture {
+
+    protected CreateReadMessageLogEvent 생성용_메시지_조회_로그;
+    protected UpdateReadMessageLogEvent 업데이트용_메시지_조회_로그;
+    protected User 메시지_로그_생성용_발신자_겸_판매자;
+    protected User 메시지_로그_생성용_입찰자_구매자;
+    protected User 메시지_로그_업데이트용_발신자_겸_판매자;
+    protected User 메시지_로그_업데이트용_입찰자;
+    protected ChatRoom 메시지_로그_생성용_채팅방;
+    protected Auction 메시지_로그_생성용_경매;
+
+    @BeforeEach
+    void setUp() {
+        메시지_로그_생성용_발신자_겸_판매자 = User.builder()
+                                   .name("메시지_로그_생성용_발신자")
+                                   .profileImage(new ProfileImage("upload.png", "store.png"))
+                                   .reliability(new Reliability(4.7d))
+                                   .oauthId("12345")
+                                   .build();
+        메시지_로그_생성용_입찰자_구매자 = User.builder()
+                                 .name("메시지_로그_생성용_입찰자")
+                                 .profileImage(new ProfileImage("upload.png", "store.png"))
+                                 .reliability(new Reliability(4.7d))
+                                 .oauthId("12346")
+                                 .build();
+        메시지_로그_업데이트용_발신자_겸_판매자 = User.builder()
+                                     .name("메시지_로그_업데이트용_발신자")
+                                     .profileImage(new ProfileImage("upload.png", "store.png"))
+                                     .reliability(new Reliability(4.7d))
+                                     .oauthId("12347")
+                                     .build();
+        메시지_로그_업데이트용_입찰자 = User.builder()
+                               .name("메시지_로그_업데이트용_입찰자")
+                               .profileImage(new ProfileImage("upload.png", "store.png"))
+                               .reliability(new Reliability(4.7d))
+                               .oauthId("12348")
+                               .build();
+
+        메시지_로그_생성용_채팅방 = new ChatRoom(메시지_로그_생성용_경매, 메시지_로그_생성용_입찰자_구매자);
+
+        final Message 메시지 = Message.builder()
+                                   .chatRoom(메시지_로그_생성용_채팅방)
+                                   .writer(메시지_로그_생성용_발신자_겸_판매자)
+                                   .contents("메시지")
+                                   .build();
+
+        업데이트용_메시지_조회_로그 = new UpdateReadMessageLogEvent(메시지_로그_생성용_발신자_겸_판매자, 메시지_로그_생성용_채팅방, 메시지);
+        생성용_메시지_조회_로그 = new CreateReadMessageLogEvent(메시지_로그_생성용_채팅방);
+    }
+}
diff --git a/backend/ddang/src/test/java/com/ddang/ddang/chat/application/fixture/LastReadMessageLogServiceFixture.java b/backend/ddang/src/test/java/com/ddang/ddang/chat/application/fixture/LastReadMessageLogServiceFixture.java
new file mode 100644
index 000000000..737969fd0
--- /dev/null
+++ b/backend/ddang/src/test/java/com/ddang/ddang/chat/application/fixture/LastReadMessageLogServiceFixture.java
@@ -0,0 +1,184 @@
+package com.ddang.ddang.chat.application.fixture;
+
+import com.ddang.ddang.auction.domain.Auction;
+import com.ddang.ddang.auction.domain.BidUnit;
+import com.ddang.ddang.auction.domain.Price;
+import com.ddang.ddang.auction.domain.repository.AuctionRepository;
+import com.ddang.ddang.auction.infrastructure.persistence.AuctionRepositoryImpl;
+import com.ddang.ddang.auction.infrastructure.persistence.JpaAuctionRepository;
+import com.ddang.ddang.auction.infrastructure.persistence.QuerydslAuctionRepository;
+import com.ddang.ddang.bid.domain.Bid;
+import com.ddang.ddang.bid.domain.BidPrice;
+import com.ddang.ddang.bid.infrastructure.persistence.BidRepositoryImpl;
+import com.ddang.ddang.bid.infrastructure.persistence.JpaBidRepository;
+import com.ddang.ddang.category.domain.Category;
+import com.ddang.ddang.category.infrastructure.persistence.JpaCategoryRepository;
+import com.ddang.ddang.chat.application.event.CreateReadMessageLogEvent;
+import com.ddang.ddang.chat.application.event.UpdateReadMessageLogEvent;
+import com.ddang.ddang.chat.domain.ChatRoom;
+import com.ddang.ddang.chat.domain.Message;
+import com.ddang.ddang.chat.domain.ReadMessageLog;
+import com.ddang.ddang.chat.domain.repository.ChatRoomRepository;
+import com.ddang.ddang.chat.domain.repository.ReadMessageLogRepository;
+import com.ddang.ddang.chat.infrastructure.persistence.ChatRoomRepositoryImpl;
+import com.ddang.ddang.chat.infrastructure.persistence.JpaChatRoomRepository;
+import com.ddang.ddang.chat.infrastructure.persistence.JpaReadMessageLogRepository;
+import com.ddang.ddang.chat.infrastructure.persistence.ReadMessageLogRepositoryImpl;
+import com.ddang.ddang.image.domain.ProfileImage;
+import com.ddang.ddang.user.domain.Reliability;
+import com.ddang.ddang.user.domain.User;
+import com.ddang.ddang.user.domain.repository.UserRepository;
+import com.ddang.ddang.user.infrastructure.persistence.JpaUserRepository;
+import com.ddang.ddang.user.infrastructure.persistence.UserRepositoryImpl;
+import com.querydsl.jpa.impl.JPAQueryFactory;
+import org.junit.jupiter.api.BeforeEach;
+import org.springframework.beans.factory.annotation.Autowired;
+
+import java.time.LocalDateTime;
+import java.util.List;
+
+@SuppressWarnings("NonAsciiCharacters")
+public class LastReadMessageLogServiceFixture {
+
+    @Autowired
+    private JpaCategoryRepository categoryRepository;
+
+    private AuctionRepository auctionRepository;
+
+    private UserRepository userRepository;
+
+    private ChatRoomRepository chatRoomRepository;
+
+    private BidRepositoryImpl bidRepository;
+
+    private ReadMessageLogRepository readMessageLogRepository;
+
+    protected CreateReadMessageLogEvent 메시지_로그_생성용_이벤트;
+    protected UpdateReadMessageLogEvent 메시지_로그_업데이트용_이벤트;
+    protected UpdateReadMessageLogEvent 유효하지_않는_메시지_조회_로그;
+    protected User 메시지_로그_생성용_발신자_겸_판매자;
+    protected User 메시지_로그_생성용_입찰자_구매자;
+    protected User 메시지_로그_업데이트용_발신자_겸_판매자;
+    protected User 메시지_로그_업데이트용_입찰자;
+    protected User 저장되지_않은_사용자;
+    protected Auction 메시지_로그_생성용_경매;
+    protected Message 메시지_로그_생성용_마지막_조회_메시지;
+    protected Message 메시지_로그_업데이트용_마지막_조회_메시지;
+    protected Auction 메시지_로그_업데이트용_경매;
+    protected ChatRoom 메시지_로그_생성용_채팅방;
+    protected ChatRoom 저장되지_않은_채팅방;
+    protected ChatRoom 메시지_로그_업데이트용_채팅방;
+
+    @BeforeEach
+    void fixtureSetUp(
+            @Autowired final JPAQueryFactory jpaQueryFactory,
+            @Autowired final JpaAuctionRepository jpaAuctionRepository,
+            @Autowired final JpaUserRepository jpaUserRepository,
+            @Autowired final JpaChatRoomRepository jpaChatRoomRepository,
+            @Autowired final JpaBidRepository jpaBidRepository,
+            @Autowired final JpaReadMessageLogRepository jpaReadMessageLogRepository
+    ) {
+        auctionRepository = new AuctionRepositoryImpl(jpaAuctionRepository, new QuerydslAuctionRepository(jpaQueryFactory));
+        userRepository = new UserRepositoryImpl(jpaUserRepository);
+        chatRoomRepository = new ChatRoomRepositoryImpl(jpaChatRoomRepository);
+        bidRepository = new BidRepositoryImpl(jpaBidRepository);
+        readMessageLogRepository = new ReadMessageLogRepositoryImpl(jpaReadMessageLogRepository);
+
+        final Category 전자기기 = new Category("전자기기");
+        final Category 전자기기_하위_노트북 = new Category("노트북");
+        전자기기.addSubCategory(전자기기_하위_노트북);
+        categoryRepository.save(전자기기);
+
+        메시지_로그_생성용_발신자_겸_판매자 = User.builder()
+                                   .name("메시지_로그_생성용_발신자")
+                                   .profileImage(new ProfileImage("upload.png", "store.png"))
+                                   .reliability(new Reliability(4.7d))
+                                   .oauthId("12345")
+                                   .build();
+        메시지_로그_생성용_입찰자_구매자 = User.builder()
+                                 .name("메시지_로그_생성용_입찰자")
+                                 .profileImage(new ProfileImage("upload.png", "store.png"))
+                                 .reliability(new Reliability(4.7d))
+                                 .oauthId("12346")
+                                 .build();
+        메시지_로그_업데이트용_발신자_겸_판매자 = User.builder()
+                                     .name("메시지_로그_업데이트용_발신자")
+                                     .profileImage(new ProfileImage("upload.png", "store.png"))
+                                     .reliability(new Reliability(4.7d))
+                                     .oauthId("12347")
+                                     .build();
+        메시지_로그_업데이트용_입찰자 = User.builder()
+                               .name("메시지_로그_업데이트용_입찰자")
+                               .profileImage(new ProfileImage("upload.png", "store.png"))
+                               .reliability(new Reliability(4.7d))
+                               .oauthId("12348")
+                               .build();
+        저장되지_않은_사용자 = User.builder()
+                          .name("저장되지_않은_사용자")
+                          .profileImage(new ProfileImage("upload.png", "store.png"))
+                          .reliability(new Reliability(4.7d))
+                          .oauthId("12349")
+                          .build();
+        userRepository.save(메시지_로그_생성용_발신자_겸_판매자);
+        userRepository.save(메시지_로그_생성용_입찰자_구매자);
+        userRepository.save(메시지_로그_업데이트용_발신자_겸_판매자);
+        userRepository.save(메시지_로그_업데이트용_입찰자);
+
+        메시지_로그_생성용_경매 = Auction.builder()
+                               .title("경매")
+                               .seller(메시지_로그_생성용_발신자_겸_판매자)
+                               .description("description")
+                               .bidUnit(new BidUnit(1_000))
+                               .startPrice(new Price(10_000))
+                               .closingTime(LocalDateTime.now().plusDays(3L))
+                               .build();
+        메시지_로그_업데이트용_경매 = Auction.builder()
+                                 .seller(메시지_로그_업데이트용_발신자_겸_판매자)
+                                 .title("메시지_로그_업데이트용_경매")
+                                 .description("description")
+                                 .bidUnit(new BidUnit(1_000))
+                                 .startPrice(new Price(10_000))
+                                 .closingTime(LocalDateTime.now().plusDays(3L))
+                                 .build();
+        auctionRepository.save(메시지_로그_생성용_경매);
+        auctionRepository.save(메시지_로그_업데이트용_경매);
+
+        final Bid 메시지_로그_생성용_입찰 = new Bid(메시지_로그_생성용_경매, 메시지_로그_생성용_입찰자_구매자, new BidPrice(15_000));
+        final Bid 메시지_로그_업데이트용_입찰 = new Bid(메시지_로그_업데이트용_경매, 메시지_로그_업데이트용_입찰자, new BidPrice(15_000));
+        bidRepository.save(메시지_로그_생성용_입찰);
+        bidRepository.save(메시지_로그_업데이트용_입찰);
+        메시지_로그_생성용_경매.updateLastBid(메시지_로그_생성용_입찰);
+        메시지_로그_업데이트용_경매.updateLastBid(메시지_로그_업데이트용_입찰);
+
+        메시지_로그_생성용_채팅방 = new ChatRoom(메시지_로그_생성용_경매, 메시지_로그_생성용_입찰자_구매자);
+        저장되지_않은_채팅방 = new ChatRoom(메시지_로그_생성용_경매, 메시지_로그_생성용_입찰자_구매자);
+        메시지_로그_업데이트용_채팅방 = new ChatRoom(메시지_로그_업데이트용_경매, 메시지_로그_업데이트용_발신자_겸_판매자);
+        chatRoomRepository.save(메시지_로그_생성용_채팅방);
+        chatRoomRepository.save(메시지_로그_업데이트용_채팅방);
+
+        메시지_로그_생성용_이벤트 = new CreateReadMessageLogEvent(메시지_로그_생성용_채팅방);
+
+        메시지_로그_생성용_마지막_조회_메시지 = Message.builder()
+                                       .writer(메시지_로그_생성용_발신자_겸_판매자)
+                                       .receiver(메시지_로그_생성용_입찰자_구매자)
+                                       .contents("메시지")
+                                       .build();
+        메시지_로그_업데이트용_마지막_조회_메시지 = Message.builder()
+                                         .writer(메시지_로그_업데이트용_발신자_겸_판매자)
+                                         .receiver(메시지_로그_업데이트용_입찰자)
+                                         .contents("메시지")
+                                         .build();
+        final Message 저장되지_않은_메시지 = Message.builder()
+                                           .writer(저장되지_않은_사용자)
+                                           .contents("저장되지 않은 메시지")
+                                           .build();
+
+        final ReadMessageLog 메시지_로그_업데이트용_로그_판매자 = new ReadMessageLog(메시지_로그_업데이트용_채팅방, 메시지_로그_업데이트용_발신자_겸_판매자);
+        final ReadMessageLog 메시지_로그_업데이트용_로그_구매자 = new ReadMessageLog(메시지_로그_업데이트용_채팅방, 메시지_로그_업데이트용_입찰자);
+        readMessageLogRepository.saveAll(List.of(메시지_로그_업데이트용_로그_판매자, 메시지_로그_업데이트용_로그_구매자));
+
+        메시지_로그_업데이트용_이벤트 = new UpdateReadMessageLogEvent(메시지_로그_업데이트용_발신자_겸_판매자, 메시지_로그_업데이트용_채팅방, 메시지_로그_업데이트용_마지막_조회_메시지);
+
+        유효하지_않는_메시지_조회_로그 = new UpdateReadMessageLogEvent(저장되지_않은_사용자, 저장되지_않은_채팅방, 저장되지_않은_메시지);
+    }
+}
diff --git a/backend/ddang/src/test/java/com/ddang/ddang/chat/application/fixture/MessageServiceFixture.java b/backend/ddang/src/test/java/com/ddang/ddang/chat/application/fixture/MessageServiceFixture.java
index 892695e39..01765bf70 100644
--- a/backend/ddang/src/test/java/com/ddang/ddang/chat/application/fixture/MessageServiceFixture.java
+++ b/backend/ddang/src/test/java/com/ddang/ddang/chat/application/fixture/MessageServiceFixture.java
@@ -49,9 +49,13 @@ public class MessageServiceFixture {
     protected ReadMessageRequest 마지막_조회_메시지_아이디가_없는_메시지_조회용_request;
     protected ReadMessageRequest 두_번째_메시지부터_모든_메시지_조회용_request;
     protected ReadMessageRequest 조회할_메시지가_더이상_없는_메시지_조회용_request;
+    protected ReadMessageRequest 조회한_마지막_메시지가_5인_메시지_조회용_request;
     protected ReadMessageRequest 유효하지_않은_사용자의_메시지_조회용_request;
     protected ReadMessageRequest 유효하지_않은_채팅방의_메시지_조회용_request;
     protected ReadMessageRequest 존재하지_않는_마지막_메시지_아이디의_메시지_조회용_request;
+    protected User 발신자;
+    protected ChatRoom 메시지가_5개인_채팅방;
+    protected Message 메시지가_5개인_채팅방_메시지의_마지막_메시지;
 
     protected String 이미지_절대_경로 = "/imageUrl";
     protected int 메시지_총_개수 = 10;
@@ -72,12 +76,12 @@ void setUp() {
                                   .build();
         auctionRepository.save(경매);
 
-        final User 발신자 = User.builder()
-                             .name("발신자")
-                             .profileImage(new ProfileImage("upload.png", "store.png"))
-                             .reliability(new Reliability(4.7d))
-                             .oauthId("12345")
-                             .build();
+        발신자 = User.builder()
+                  .name("발신자")
+                  .profileImage(new ProfileImage("upload.png", "store.png"))
+                  .reliability(new Reliability(4.7d))
+                  .oauthId("12345")
+                  .build();
         final User 수신자 = User.builder()
                              .name("수신자")
                              .profileImage(new ProfileImage("upload.png", "store.png"))
@@ -97,9 +101,11 @@ void setUp() {
 
         final ChatRoom 채팅방 = new ChatRoom(경매, 발신자);
         final ChatRoom 탈퇴한_사용자와의_채팅방 = new ChatRoom(경매, 탈퇴한_사용자);
+        메시지가_5개인_채팅방 = new ChatRoom(경매, 발신자);
 
         chatRoomRepository.save(채팅방);
         chatRoomRepository.save(탈퇴한_사용자와의_채팅방);
+        chatRoomRepository.save(메시지가_5개인_채팅방);
 
         메시지_생성_DTO = new CreateMessageDto(
                 채팅방.getId(),
@@ -144,6 +150,19 @@ void setUp() {
             messageRepository.save(메시지);
         }
 
+        final List<Message> 메시지가_5개인_채팅방_메시지들 = new ArrayList<>();
+        for (int count = 0; count < 5; count++) {
+            final Message 메시지 = Message.builder()
+                                       .writer(발신자)
+                                       .receiver(수신자)
+                                       .chatRoom(메시지가_5개인_채팅방)
+                                       .contents("메시지 내용")
+                                       .build();
+            메시지가_5개인_채팅방_메시지들.add(메시지);
+            messageRepository.save(메시지);
+        }
+        메시지가_5개인_채팅방_메시지의_마지막_메시지 = 메시지가_5개인_채팅방_메시지들.get(4);
+
         마지막_조회_메시지_아이디가_없는_메시지_조회용_request = new ReadMessageRequest(발신자.getId(), 채팅방.getId(), null);
         두_번째_메시지부터_모든_메시지_조회용_request = new ReadMessageRequest(발신자.getId(), 채팅방.getId(), 메시지들.get(0).getId());
         조회할_메시지가_더이상_없는_메시지_조회용_request = new ReadMessageRequest(발신자.getId(), 채팅방.getId(), 메시지들.get(메시지_총_개수 - 1)
@@ -151,5 +170,6 @@ void setUp() {
         유효하지_않은_사용자의_메시지_조회용_request = new ReadMessageRequest(-999L, 채팅방.getId(), null);
         유효하지_않은_채팅방의_메시지_조회용_request = new ReadMessageRequest(발신자.getId(), -999L, null);
         존재하지_않는_마지막_메시지_아이디의_메시지_조회용_request = new ReadMessageRequest(발신자.getId(), 채팅방.getId(), -999L);
+        조회한_마지막_메시지가_5인_메시지_조회용_request = new ReadMessageRequest(발신자.getId(), 메시지가_5개인_채팅방.getId(), null);
     }
 }
diff --git a/backend/ddang/src/test/java/com/ddang/ddang/chat/infrastructure/persistence/JpaMessageRepositoryTest.java b/backend/ddang/src/test/java/com/ddang/ddang/chat/infrastructure/persistence/JpaMessageRepositoryTest.java
index 0cb97b3e3..c12aa23f4 100644
--- a/backend/ddang/src/test/java/com/ddang/ddang/chat/infrastructure/persistence/JpaMessageRepositoryTest.java
+++ b/backend/ddang/src/test/java/com/ddang/ddang/chat/infrastructure/persistence/JpaMessageRepositoryTest.java
@@ -4,8 +4,6 @@
 import com.ddang.ddang.chat.infrastructure.persistence.fixture.JpaMessageRepositoryFixture;
 import com.ddang.ddang.configuration.JpaConfiguration;
 import com.ddang.ddang.configuration.QuerydslConfiguration;
-import jakarta.persistence.EntityManager;
-import jakarta.persistence.PersistenceContext;
 import org.junit.jupiter.api.DisplayNameGeneration;
 import org.junit.jupiter.api.DisplayNameGenerator;
 import org.junit.jupiter.api.Test;
diff --git a/backend/ddang/src/test/java/com/ddang/ddang/chat/infrastructure/persistence/QuerydslChatRoomAndMessageAndImageRepositoryTest.java b/backend/ddang/src/test/java/com/ddang/ddang/chat/infrastructure/persistence/QuerydslChatRoomAndMessageAndImageRepositoryTest.java
index 694cb6999..fc55b97c7 100644
--- a/backend/ddang/src/test/java/com/ddang/ddang/chat/infrastructure/persistence/QuerydslChatRoomAndMessageAndImageRepositoryTest.java
+++ b/backend/ddang/src/test/java/com/ddang/ddang/chat/infrastructure/persistence/QuerydslChatRoomAndMessageAndImageRepositoryTest.java
@@ -1,6 +1,9 @@
 package com.ddang.ddang.chat.infrastructure.persistence;
 
+import com.ddang.ddang.chat.domain.ReadMessageLog;
 import com.ddang.ddang.chat.domain.dto.ChatRoomAndMessageAndImageDto;
+import com.ddang.ddang.chat.domain.repository.MessageRepository;
+import com.ddang.ddang.chat.domain.repository.ReadMessageLogRepository;
 import com.ddang.ddang.chat.infrastructure.persistence.fixture.QuerydslChatRoomAndMessageAndImageRepositoryFixture;
 import com.ddang.ddang.configuration.JpaConfiguration;
 import com.ddang.ddang.configuration.QuerydslConfiguration;
@@ -24,9 +27,41 @@ class QuerydslChatRoomAndMessageAndImageRepositoryTest extends QuerydslChatRoomA
 
     QuerydslChatRoomAndMessageAndImageRepository querydslChatRoomAndMessageAndImageRepository;
 
+    ReadMessageLogRepository readMessageLogRepository;
+
+    MessageRepository messageRepository;
+
     @BeforeEach
-    void setUp(@Autowired final JPAQueryFactory queryFactory) {
+    void setUp(
+            @Autowired final JPAQueryFactory queryFactory,
+            @Autowired final JpaReadMessageLogRepository jpaReadMessageLogRepository,
+            @Autowired final JpaMessageRepository jpaMessageRepository
+    ) {
         querydslChatRoomAndMessageAndImageRepository = new QuerydslChatRoomAndMessageAndImageRepository(queryFactory);
+        readMessageLogRepository = new ReadMessageLogRepositoryImpl(jpaReadMessageLogRepository);
+        messageRepository = new MessageRepositoryImpl(jpaMessageRepository, new QuerydslMessageRepository(queryFactory));
+    }
+
+    @Test
+    void 사용자가_읽지_않은_메시지_개수를_반환한다() {
+        // given
+        readMessageLogRepository.saveAll(List.of(new ReadMessageLog(메리_엔초_채팅방, 메리), new ReadMessageLog(메리_엔초_채팅방, 엔초)));
+
+        // when
+        messageRepository.save(메리가_엔초에게_3시에_보낸_쪽지1);
+        messageRepository.save(메리가_엔초에게_3시에_보낸_쪽지2);
+        messageRepository.save(메리가_엔초에게_3시에_보낸_쪽지3);
+        messageRepository.save(엔초가_메리에게_3시에_보낸_쪽지);
+        final List<ChatRoomAndMessageAndImageDto> actual_엔초 = querydslChatRoomAndMessageAndImageRepository
+                .findAllChatRoomInfoByUserIdOrderByLastMessage(엔초.getId());
+        final List<ChatRoomAndMessageAndImageDto> actual_메리 = querydslChatRoomAndMessageAndImageRepository
+                .findAllChatRoomInfoByUserIdOrderByLastMessage(메리.getId());
+
+        // then
+        SoftAssertions.assertSoftly(softAssertions -> {
+            softAssertions.assertThat(actual_엔초.get(0).unreadMessageCount()).isEqualTo(3);
+            softAssertions.assertThat(actual_메리.get(0).unreadMessageCount()).isEqualTo(1);
+        });
     }
 
     @Test
@@ -37,16 +72,13 @@ void setUp(@Autowired final JPAQueryFactory queryFactory) {
 
         // then
         SoftAssertions.assertSoftly(softAssertions -> {
-            softAssertions.assertThat(actual).hasSize(3);
+            softAssertions.assertThat(actual).hasSize(2);
             softAssertions.assertThat(actual.get(0).chatRoom()).isEqualTo(엔초_지토_채팅방);
             softAssertions.assertThat(actual.get(0).message()).isEqualTo(엔초가_지토에게_5시에_보낸_쪽지);
             softAssertions.assertThat(actual.get(0).thumbnailImage()).isEqualTo(엔초의_경매_대표_이미지);
             softAssertions.assertThat(actual.get(1).chatRoom()).isEqualTo(제이미_엔초_채팅방);
             softAssertions.assertThat(actual.get(1).message()).isEqualTo(제이미가_엔초에게_4시에_보낸_쪽지);
             softAssertions.assertThat(actual.get(1).thumbnailImage()).isEqualTo(제이미의_경매_대표_이미지);
-            softAssertions.assertThat(actual.get(2).chatRoom()).isEqualTo(메리_엔초_채팅방);
-            softAssertions.assertThat(actual.get(2).message()).isEqualTo(메리가_엔초에게_3시에_보낸_쪽지);
-            softAssertions.assertThat(actual.get(2).thumbnailImage()).isEqualTo(메리의_경매_대표_이미지);
         });
     }
 }
diff --git a/backend/ddang/src/test/java/com/ddang/ddang/chat/infrastructure/persistence/ReadMessageLogRepositoryImplTest.java b/backend/ddang/src/test/java/com/ddang/ddang/chat/infrastructure/persistence/ReadMessageLogRepositoryImplTest.java
new file mode 100644
index 000000000..ad254efd8
--- /dev/null
+++ b/backend/ddang/src/test/java/com/ddang/ddang/chat/infrastructure/persistence/ReadMessageLogRepositoryImplTest.java
@@ -0,0 +1,55 @@
+package com.ddang.ddang.chat.infrastructure.persistence;
+
+import com.ddang.ddang.chat.domain.ReadMessageLog;
+import com.ddang.ddang.chat.domain.repository.ReadMessageLogRepository;
+import com.ddang.ddang.chat.infrastructure.persistence.fixture.ReadMessageLogRepositoryFixture;
+import com.ddang.ddang.configuration.JpaConfiguration;
+import com.ddang.ddang.configuration.QuerydslConfiguration;
+import org.assertj.core.api.SoftAssertions;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.DisplayNameGeneration;
+import org.junit.jupiter.api.DisplayNameGenerator;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.autoconfigure.orm.jpa.DataJpaTest;
+import org.springframework.context.annotation.Import;
+
+import java.util.List;
+import java.util.Optional;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+@DataJpaTest
+@Import({JpaConfiguration.class, QuerydslConfiguration.class})
+@DisplayNameGeneration(DisplayNameGenerator.ReplaceUnderscores.class)
+@SuppressWarnings("NonAsciiCharacters")
+class ReadMessageLogRepositoryImplTest extends ReadMessageLogRepositoryFixture {
+
+    ReadMessageLogRepository readMessageLogRepository;
+
+    @BeforeEach
+    void setUp(@Autowired final JpaReadMessageLogRepository jpaReadMessageLogRepository) {
+        readMessageLogRepository = new ReadMessageLogRepositoryImpl(jpaReadMessageLogRepository);
+    }
+
+    @Test
+    void 마지막_읽은_메시지를_저장한다() {
+        // given
+        final ReadMessageLog actual = readMessageLogRepository.saveAll(List.of(다섯_번째_메시지까지_읽은_메시지_로그)).get(0);
+
+        // then
+        assertThat(actual.getId()).isPositive();
+    }
+
+    @Test
+    void 메시지_조회자_아이디와_채팅방_아이디에_해당하는_조회_메시지_로그를_반환한다() {
+        // given
+        final Optional<ReadMessageLog> actual = readMessageLogRepository.findBy(메리.getId(), 메리_엔초_채팅방.getId());
+
+        // then
+        SoftAssertions.assertSoftly(softAssertions -> {
+            softAssertions.assertThat(actual).isPresent();
+            softAssertions.assertThat(actual.get().getLastReadMessageId()).isEqualTo(다섯_번째_메시지.getId());
+        });
+    }
+}
diff --git a/backend/ddang/src/test/java/com/ddang/ddang/chat/infrastructure/persistence/fixture/QuerydslChatRoomAndMessageAndImageRepositoryFixture.java b/backend/ddang/src/test/java/com/ddang/ddang/chat/infrastructure/persistence/fixture/QuerydslChatRoomAndMessageAndImageRepositoryFixture.java
index 49bdf7e18..357cbf052 100644
--- a/backend/ddang/src/test/java/com/ddang/ddang/chat/infrastructure/persistence/fixture/QuerydslChatRoomAndMessageAndImageRepositoryFixture.java
+++ b/backend/ddang/src/test/java/com/ddang/ddang/chat/infrastructure/persistence/fixture/QuerydslChatRoomAndMessageAndImageRepositoryFixture.java
@@ -58,15 +58,20 @@ public class QuerydslChatRoomAndMessageAndImageRepositoryFixture {
     private JpaMessageRepository messageRepository;
 
     protected User 엔초;
+    protected User 메리;
     protected AuctionImage 메리의_경매_대표_이미지;
     protected AuctionImage 엔초의_경매_대표_이미지;
     protected AuctionImage 제이미의_경매_대표_이미지;
     protected ChatRoom 메리_엔초_채팅방;
     protected ChatRoom 엔초_지토_채팅방;
     protected ChatRoom 제이미_엔초_채팅방;
-    protected Message 메리가_엔초에게_3시에_보낸_쪽지;
     protected Message 제이미가_엔초에게_4시에_보낸_쪽지;
     protected Message 엔초가_지토에게_5시에_보낸_쪽지;
+    protected Message 엔초가_지토에게_추가로_보낸_쪽지;
+    protected Message 메리가_엔초에게_3시에_보낸_쪽지1;
+    protected Message 메리가_엔초에게_3시에_보낸_쪽지2;
+    protected Message 메리가_엔초에게_3시에_보낸_쪽지3;
+    protected Message 엔초가_메리에게_3시에_보낸_쪽지;
 
     @BeforeEach
     void setUp() {
@@ -80,24 +85,24 @@ void setUp() {
                  .reliability(new Reliability(4.7d))
                  .oauthId("12346")
                  .build();
-        final User 메리 = User.builder()
-                             .name("메리")
-                             .profileImage(프로필_이미지)
-                             .reliability(new Reliability(4.7d))
-                             .oauthId("12345")
-                             .build();
+        메리 = User.builder()
+                 .name("메리")
+                 .profileImage(프로필_이미지)
+                 .reliability(new Reliability(4.7d))
+                 .oauthId("12345")
+                 .build();
         final User 제이미 = User.builder()
-                              .name("제이미")
-                              .profileImage(프로필_이미지)
-                              .reliability(new Reliability(4.7d))
-                              .oauthId("12347")
-                              .build();
-        final User 지토 = User.builder()
-                             .name("지토")
+                             .name("제이미")
                              .profileImage(프로필_이미지)
                              .reliability(new Reliability(4.7d))
-                             .oauthId("12348")
+                             .oauthId("12347")
                              .build();
+        final User 지토 = User.builder()
+                            .name("지토")
+                            .profileImage(프로필_이미지)
+                            .reliability(new Reliability(4.7d))
+                            .oauthId("12348")
+                            .build();
 
         메리의_경매_대표_이미지 = new AuctionImage("메리의_경매_대표_이미지.png", "메리의_경매_대표_이미지.png");
         final AuctionImage 메리의_대표_이미지가_아닌_경매_이미지 =
@@ -110,32 +115,32 @@ void setUp() {
                 new AuctionImage("제이미의_대표 이미지가_아닌_경매_이미지.png", "제이미의_대표 이미지가_아닌_경매_이미지.png");
 
         final Auction 메리의_경매 = Auction.builder()
-                                        .seller(메리)
-                                        .title("메리 맥북")
-                                        .description("메리 맥북 팔아요")
-                                        .subCategory(전자기기_서브_노트북_카테고리)
-                                        .startPrice(new Price(10_000))
-                                        .bidUnit(new BidUnit(1_000))
-                                        .closingTime(LocalDateTime.now())
-                                        .build();
+                                      .seller(메리)
+                                      .title("메리 맥북")
+                                      .description("메리 맥북 팔아요")
+                                      .subCategory(전자기기_서브_노트북_카테고리)
+                                      .startPrice(new Price(10_000))
+                                      .bidUnit(new BidUnit(1_000))
+                                      .closingTime(LocalDateTime.now())
+                                      .build();
         final Auction 엔초의_경매 = Auction.builder()
-                                        .seller(엔초)
-                                        .title("엔초 맥북")
-                                        .description("엔초 맥북 팔아요")
-                                        .subCategory(전자기기_서브_노트북_카테고리)
-                                        .startPrice(new Price(10_000))
-                                        .bidUnit(new BidUnit(1_000))
-                                        .closingTime(LocalDateTime.now())
-                                        .build();
+                                      .seller(엔초)
+                                      .title("엔초 맥북")
+                                      .description("엔초 맥북 팔아요")
+                                      .subCategory(전자기기_서브_노트북_카테고리)
+                                      .startPrice(new Price(10_000))
+                                      .bidUnit(new BidUnit(1_000))
+                                      .closingTime(LocalDateTime.now())
+                                      .build();
         final Auction 제이미의_경매 = Auction.builder()
-                                          .seller(제이미)
-                                          .title("제이미 맥북")
-                                          .description("제이미 맥북 팔아요")
-                                          .subCategory(전자기기_서브_노트북_카테고리)
-                                          .startPrice(new Price(10_000))
-                                          .bidUnit(new BidUnit(1_000))
-                                          .closingTime(LocalDateTime.now())
-                                          .build();
+                                       .seller(제이미)
+                                       .title("제이미 맥북")
+                                       .description("제이미 맥북 팔아요")
+                                       .subCategory(전자기기_서브_노트북_카테고리)
+                                       .startPrice(new Price(10_000))
+                                       .bidUnit(new BidUnit(1_000))
+                                       .closingTime(LocalDateTime.now())
+                                       .build();
 
         final Bid 엔초가_메리_경매에_입찰 = new Bid(메리의_경매, 엔초, new BidPrice(15_000));
         final Bid 지토가_엔초_경매에_입찰 = new Bid(엔초의_경매, 지토, new BidPrice(15_000));
@@ -146,36 +151,65 @@ void setUp() {
         제이미_엔초_채팅방 = new ChatRoom(제이미의_경매, 엔초);
 
         final Message 제이미가_엔초에게_1시에_보낸_쪽지 = Message.builder()
-                                                         .chatRoom(제이미_엔초_채팅방)
-                                                         .contents("제이미가 엔초에게 1시애 보낸 쪽지")
-                                                         .writer(제이미)
-                                                         .receiver(엔초)
-                                                         .build();
+                                                   .chatRoom(제이미_엔초_채팅방)
+                                                   .contents("제이미가 엔초에게 1시애 보낸 쪽지")
+                                                   .writer(제이미)
+                                                   .receiver(엔초)
+                                                   .build();
         final Message 엔초가_지토에게_2시에_보낸_쪽지 = Message.builder()
-                                                        .chatRoom(엔초_지토_채팅방)
-                                                        .contents("엔초가 지토에게 2시애 보낸 쪽지")
-                                                        .writer(엔초)
-                                                        .receiver(지토)
-                                                        .build();
-        메리가_엔초에게_3시에_보낸_쪽지 = Message.builder()
-                                          .chatRoom(메리_엔초_채팅방)
-                                          .contents("메리가 엔초에게 3시에 보낸 쪽지")
-                                          .writer(엔초)
-                                          .receiver(지토)
-                                          .build();
+                                                  .chatRoom(엔초_지토_채팅방)
+                                                  .contents("엔초가 지토에게 2시애 보낸 쪽지")
+                                                  .writer(엔초)
+                                                  .receiver(지토)
+                                                  .build();
         제이미가_엔초에게_4시에_보낸_쪽지 = Message.builder()
-                                           .chatRoom(제이미_엔초_채팅방)
-                                           .contents("제이미가 엔초에게 4시애 보낸 쪽지")
-                                           .writer(제이미)
-                                           .receiver(엔초)
-                                           .build();
+                                     .chatRoom(제이미_엔초_채팅방)
+                                     .contents("제이미가 엔초에게 4시애 보낸 쪽지")
+                                     .writer(제이미)
+                                     .receiver(엔초)
+                                     .build();
         엔초가_지토에게_5시에_보낸_쪽지 = Message.builder()
-                                          .chatRoom(엔초_지토_채팅방)
-                                          .contents("엔초가 지토에게 5시애 보낸 쪽지")
-                                          .writer(엔초)
-                                          .receiver(지토)
-                                          .build();
-
+                                    .chatRoom(엔초_지토_채팅방)
+                                    .contents("엔초가 지토에게 5시애 보낸 쪽지")
+                                    .writer(엔초)
+                                    .receiver(지토)
+                                    .build();
+        엔초가_지토에게_추가로_보낸_쪽지 = Message.builder()
+                                    .chatRoom(엔초_지토_채팅방)
+                                    .contents("엔초가 지토에게 6시애 보낸 쪽지")
+                                    .writer(엔초)
+                                    .receiver(지토)
+                                    .build();
+        메리가_엔초에게_3시에_보낸_쪽지1 = Message.builder()
+                                     .chatRoom(메리_엔초_채팅방)
+                                     .contents("메리가 엔초에게 3시에 보낸 쪽지")
+                                     .writer(메리)
+                                     .receiver(엔초)
+                                     .build();
+        메리가_엔초에게_3시에_보낸_쪽지1 = Message.builder()
+                                     .chatRoom(메리_엔초_채팅방)
+                                     .contents("메리가 엔초에게 3시에 보낸 쪽지2")
+                                     .writer(메리)
+                                     .receiver(엔초)
+                                     .build();
+        메리가_엔초에게_3시에_보낸_쪽지2 = Message.builder()
+                                     .chatRoom(메리_엔초_채팅방)
+                                     .contents("메리가 엔초에게 3시에 보낸 쪽지3")
+                                     .writer(메리)
+                                     .receiver(엔초)
+                                     .build();
+        메리가_엔초에게_3시에_보낸_쪽지3 = Message.builder()
+                                     .chatRoom(메리_엔초_채팅방)
+                                     .contents("메리가 엔초에게 3시에 보낸 쪽지3")
+                                     .writer(메리)
+                                     .receiver(엔초)
+                                     .build();
+        엔초가_메리에게_3시에_보낸_쪽지 = Message.builder()
+                                    .chatRoom(메리_엔초_채팅방)
+                                    .contents("엔초가 메리에게 3시에 보낸 쪽지3")
+                                    .writer(엔초)
+                                    .receiver(메리)
+                                    .build();
 
         전자기기_카테고리.addSubCategory(전자기기_서브_노트북_카테고리);
         categoryRepository.save(전자기기_카테고리);
@@ -206,7 +240,6 @@ void setUp() {
                 List.of(
                         제이미가_엔초에게_1시에_보낸_쪽지,
                         엔초가_지토에게_2시에_보낸_쪽지,
-                        메리가_엔초에게_3시에_보낸_쪽지,
                         제이미가_엔초에게_4시에_보낸_쪽지,
                         엔초가_지토에게_5시에_보낸_쪽지
                 )
diff --git a/backend/ddang/src/test/java/com/ddang/ddang/chat/infrastructure/persistence/fixture/ReadMessageLogRepositoryFixture.java b/backend/ddang/src/test/java/com/ddang/ddang/chat/infrastructure/persistence/fixture/ReadMessageLogRepositoryFixture.java
new file mode 100644
index 000000000..02c48e537
--- /dev/null
+++ b/backend/ddang/src/test/java/com/ddang/ddang/chat/infrastructure/persistence/fixture/ReadMessageLogRepositoryFixture.java
@@ -0,0 +1,149 @@
+package com.ddang.ddang.chat.infrastructure.persistence.fixture;
+
+import com.ddang.ddang.auction.domain.Auction;
+import com.ddang.ddang.auction.domain.BidUnit;
+import com.ddang.ddang.auction.domain.Price;
+import com.ddang.ddang.auction.domain.repository.AuctionRepository;
+import com.ddang.ddang.auction.infrastructure.persistence.AuctionRepositoryImpl;
+import com.ddang.ddang.auction.infrastructure.persistence.JpaAuctionRepository;
+import com.ddang.ddang.auction.infrastructure.persistence.QuerydslAuctionRepository;
+import com.ddang.ddang.bid.domain.Bid;
+import com.ddang.ddang.bid.domain.BidPrice;
+import com.ddang.ddang.bid.domain.repository.BidRepository;
+import com.ddang.ddang.bid.infrastructure.persistence.BidRepositoryImpl;
+import com.ddang.ddang.bid.infrastructure.persistence.JpaBidRepository;
+import com.ddang.ddang.category.domain.Category;
+import com.ddang.ddang.category.infrastructure.persistence.JpaCategoryRepository;
+import com.ddang.ddang.chat.domain.ChatRoom;
+import com.ddang.ddang.chat.domain.Message;
+import com.ddang.ddang.chat.domain.ReadMessageLog;
+import com.ddang.ddang.chat.domain.repository.ChatRoomRepository;
+import com.ddang.ddang.chat.domain.repository.MessageRepository;
+import com.ddang.ddang.chat.infrastructure.persistence.ChatRoomRepositoryImpl;
+import com.ddang.ddang.chat.infrastructure.persistence.JpaChatRoomRepository;
+import com.ddang.ddang.chat.infrastructure.persistence.JpaMessageRepository;
+import com.ddang.ddang.chat.infrastructure.persistence.JpaReadMessageLogRepository;
+import com.ddang.ddang.chat.infrastructure.persistence.MessageRepositoryImpl;
+import com.ddang.ddang.chat.infrastructure.persistence.QuerydslMessageRepository;
+import com.ddang.ddang.chat.infrastructure.persistence.ReadMessageLogRepositoryImpl;
+import com.ddang.ddang.image.domain.AuctionImage;
+import com.ddang.ddang.image.domain.ProfileImage;
+import com.ddang.ddang.user.domain.Reliability;
+import com.ddang.ddang.user.domain.User;
+import com.ddang.ddang.user.domain.repository.UserRepository;
+import com.ddang.ddang.user.infrastructure.persistence.JpaUserRepository;
+import com.ddang.ddang.user.infrastructure.persistence.UserRepositoryImpl;
+import com.querydsl.jpa.impl.JPAQueryFactory;
+import org.junit.jupiter.api.BeforeEach;
+import org.springframework.beans.factory.annotation.Autowired;
+
+import java.time.LocalDateTime;
+import java.util.ArrayList;
+import java.util.List;
+
+@SuppressWarnings("NonAsciiCharacters")
+public class ReadMessageLogRepositoryFixture {
+
+    @Autowired
+    private JpaCategoryRepository categoryRepository;
+
+    private AuctionRepository auctionRepository;
+
+    private UserRepository userRepository;
+
+    private BidRepository bidRepository;
+
+    private ChatRoomRepository chatRoomRepository;
+
+    private MessageRepository messageRepository;
+
+    private ReadMessageLogRepositoryImpl readMessageLogRepository;
+
+    protected ChatRoom 메리_엔초_채팅방;
+    protected User 메리;
+    protected User 엔초;
+    protected ReadMessageLog 다섯_번째_메시지까지_읽은_메시지_로그;
+    protected Message 다섯_번째_메시지;
+
+    protected AuctionImage 메리의_경매_대표_이미지 = new AuctionImage("메리_경매_대표_이미지.png", "메리의_경매_대표_이미지.png");
+    protected AuctionImage 메리의_대표_이미지가_아닌_경매_이미지 = new AuctionImage("메리의_대표 이미지가_아닌_경매_이미지.png", "메리의_대표 이미지가_아닌_경매_이미지.png");
+    protected ProfileImage 프로필_이미지 = new ProfileImage("upload.png", "store.png");
+
+    @BeforeEach
+    void fixtureSetUp(
+            @Autowired final JPAQueryFactory jpaQueryFactory,
+            @Autowired final JpaAuctionRepository jpaAuctionRepository,
+            @Autowired final JpaUserRepository jpaUserRepository,
+            @Autowired final JpaBidRepository jpaBidRepository,
+            @Autowired final JpaChatRoomRepository jpaChatRoomRepository,
+            @Autowired final JpaMessageRepository jpaMessageRepository,
+            @Autowired final JpaReadMessageLogRepository jpaReadMessageLogRepository
+    ) {
+        auctionRepository = new AuctionRepositoryImpl(jpaAuctionRepository, new QuerydslAuctionRepository(jpaQueryFactory));
+        userRepository = new UserRepositoryImpl(jpaUserRepository);
+        bidRepository = new BidRepositoryImpl(jpaBidRepository);
+        chatRoomRepository = new ChatRoomRepositoryImpl(jpaChatRoomRepository);
+        messageRepository = new MessageRepositoryImpl(jpaMessageRepository, new QuerydslMessageRepository(jpaQueryFactory));
+        readMessageLogRepository = new ReadMessageLogRepositoryImpl(jpaReadMessageLogRepository);
+
+        final Category 전자기기_카테고리 = new Category("전자기기");
+        final Category 전자기기_서브_노트북_카테고리 = new Category("노트북 카테고리");
+        전자기기_카테고리.addSubCategory(전자기기_서브_노트북_카테고리);
+        categoryRepository.save(전자기기_카테고리);
+
+        메리 = User.builder()
+                 .name("메리_판매자")
+                 .profileImage(프로필_이미지)
+                 .reliability(new Reliability(4.7d))
+                 .oauthId("12345")
+                 .build();
+        엔초 = User.builder()
+                 .name("엔초_구매자")
+                 .profileImage(프로필_이미지)
+                 .reliability(new Reliability(4.7d))
+                 .oauthId("14567")
+                 .build();
+        userRepository.save(메리);
+        userRepository.save(엔초);
+
+        final Auction 판매자_메리_구매자_엔초_경매 = Auction.builder()
+                                                .seller(메리)
+                                                .title("메리 맥북")
+                                                .description("메리 맥북 팔아요")
+                                                .subCategory(전자기기_서브_노트북_카테고리)
+                                                .startPrice(new Price(10_000))
+                                                .bidUnit(new BidUnit(1_000))
+                                                .closingTime(LocalDateTime.now())
+                                                .build();
+        판매자_메리_구매자_엔초_경매.addAuctionImages(List.of(메리의_경매_대표_이미지, 메리의_대표_이미지가_아닌_경매_이미지));
+        auctionRepository.save(판매자_메리_구매자_엔초_경매);
+
+
+        final Bid 엔초가_메리_경매에_입찰 = new Bid(판매자_메리_구매자_엔초_경매, 엔초, new BidPrice(15_000));
+        bidRepository.save(엔초가_메리_경매에_입찰);
+
+        판매자_메리_구매자_엔초_경매.updateLastBid(엔초가_메리_경매에_입찰);
+        메리_엔초_채팅방 = new ChatRoom(판매자_메리_구매자_엔초_경매, 엔초);
+        chatRoomRepository.save(메리_엔초_채팅방);
+
+        List<Message> 메리_엔초_메시지들 = new ArrayList<>();
+        for (int i = 0; i < 10; i++) {
+            final Message 메시지 = Message.builder()
+                                       .chatRoom(메리_엔초_채팅방)
+                                       .writer(메리)
+                                       .receiver(엔초)
+                                       .contents("안녕하세요")
+                                       .build();
+            messageRepository.save(메시지);
+            메리_엔초_메시지들.add(메시지);
+        }
+
+        다섯_번째_메시지 = 메리_엔초_메시지들.get(4);
+        다섯_번째_메시지까지_읽은_메시지_로그 = new ReadMessageLog(메리_엔초_채팅방, 메리);
+        다섯_번째_메시지까지_읽은_메시지_로그.updateLastReadMessage(다섯_번째_메시지.getId());
+
+        final ReadMessageLog 메리_엔초_채팅방의_메리_메시지_조회_로그 = new ReadMessageLog(메리_엔초_채팅방, 메리);
+        메리_엔초_채팅방의_메리_메시지_조회_로그.updateLastReadMessage(다섯_번째_메시지.getId());
+        readMessageLogRepository.saveAll(List.of(메리_엔초_채팅방의_메리_메시지_조회_로그));
+    }
+}
diff --git a/backend/ddang/src/test/java/com/ddang/ddang/chat/presentation/ChatRoomControllerTest.java b/backend/ddang/src/test/java/com/ddang/ddang/chat/presentation/ChatRoomControllerTest.java
index 76b29dda0..d0f948c66 100644
--- a/backend/ddang/src/test/java/com/ddang/ddang/chat/presentation/ChatRoomControllerTest.java
+++ b/backend/ddang/src/test/java/com/ddang/ddang/chat/presentation/ChatRoomControllerTest.java
@@ -247,13 +247,15 @@ void setUp() {
                                                                                                       .title())),
                                                            jsonPath("$.[0].lastMessage.contents", is(조회용_채팅방1.lastMessageDto()
                                                                                                              .contents())),
+                                                           jsonPath("$.[0].unreadMessageCount", is(조회용_채팅방1.unreadMessageCount()), Long.class),
                                                            jsonPath("$.[1].id", is(조회용_채팅방2.id()), Long.class),
                                                            jsonPath("$.[1].chatPartner.name", is(조회용_채팅방2.partnerDto()
                                                                                                          .name())),
                                                            jsonPath("$.[1].auction.title", is(조회용_채팅방2.auctionDto()
                                                                                                       .title())),
                                                            jsonPath("$.[1].lastMessage.contents", is(조회용_채팅방2.lastMessageDto()
-                                                                                                             .contents()))
+                                                                                                             .contents())),
+                                                           jsonPath("$.[1].unreadMessageCount", is(조회용_채팅방1.unreadMessageCount()), Long.class)
                                                    );
         readAllParticipatingChatRooms_문서화(resultActions);
     }
@@ -539,6 +541,8 @@ void setUp() {
                                                                          .description("메시지를 보낸 시간"),
                                 fieldWithPath("[].lastMessage.contents").type(JsonFieldType.STRING)
                                                                         .description("메시지 내용"),
+                                fieldWithPath("[].unreadMessageCount").type(JsonFieldType.NUMBER)
+                                                                      .description("안 읽은 메시지 개수"),
                                 fieldWithPath("[].isChatAvailable").type(JsonFieldType.BOOLEAN)
                                                                    .description("채팅 가능 여부")
                         )
diff --git a/backend/ddang/src/test/java/com/ddang/ddang/chat/presentation/fixture/ChatRoomControllerFixture.java b/backend/ddang/src/test/java/com/ddang/ddang/chat/presentation/fixture/ChatRoomControllerFixture.java
index 8f7b5ddaa..6d83db0e4 100644
--- a/backend/ddang/src/test/java/com/ddang/ddang/chat/presentation/fixture/ChatRoomControllerFixture.java
+++ b/backend/ddang/src/test/java/com/ddang/ddang/chat/presentation/fixture/ChatRoomControllerFixture.java
@@ -23,8 +23,8 @@ public class ChatRoomControllerFixture extends CommonControllerSliceTest {
     private ReadUserInChatRoomDto 구매자2 = new ReadUserInChatRoomDto(3L, "구매자2", 3L, 5.0d, false);
     private ReadAuctionInChatRoomDto 조회용_경매1 = new ReadAuctionInChatRoomDto(1L, "경매1", 10_000, 1L);
     private ReadAuctionInChatRoomDto 조회용_경매2 = new ReadAuctionInChatRoomDto(2L, "경매2", 20_000, 1L);
-    protected ReadChatRoomWithLastMessageDto 조회용_채팅방1 = new ReadChatRoomWithLastMessageDto(1L, 조회용_경매1, 구매자1, new ReadLastMessageDto(1L, LocalDateTime.now(), 판매자, 구매자1, "메시지1"), true);
-    protected ReadChatRoomWithLastMessageDto 조회용_채팅방2 = new ReadChatRoomWithLastMessageDto(2L, 조회용_경매2, 구매자2, new ReadLastMessageDto(1L, LocalDateTime.now(), 판매자, 구매자2, "메시지2"), true);
+    protected ReadChatRoomWithLastMessageDto 조회용_채팅방1 = new ReadChatRoomWithLastMessageDto(1L, 조회용_경매1, 구매자1, new ReadLastMessageDto(1L, LocalDateTime.now(), 판매자, 구매자1, "메시지1"), 1L, true);
+    protected ReadChatRoomWithLastMessageDto 조회용_채팅방2 = new ReadChatRoomWithLastMessageDto(2L, 조회용_경매2, 구매자2, new ReadLastMessageDto(1L, LocalDateTime.now(), 판매자, 구매자2, "메시지2"), 1L, true);
     protected CreateMessageRequest 메시지_생성_요청 = new CreateMessageRequest(1L, "메시지 내용");
     protected CreateMessageRequest 유효하지_않은_발신자의_메시지_생성_요청 = new CreateMessageRequest(-999L, "메시지 내용");
     protected CreateMessageRequest 탈퇴한_사용자와의_메시지_생성_요청 = new CreateMessageRequest(탈퇴한_사용자_아이디, "메시지 내용");