diff --git a/src/main/java/corecord/dev/domain/chat/dto/request/ChatRequest.java b/src/main/java/corecord/dev/domain/chat/dto/request/ChatRequest.java
index 270c1d7..18d7f9d 100644
--- a/src/main/java/corecord/dev/domain/chat/dto/request/ChatRequest.java
+++ b/src/main/java/corecord/dev/domain/chat/dto/request/ChatRequest.java
@@ -1,11 +1,13 @@
 package corecord.dev.domain.chat.dto.request;
 
 import jakarta.validation.constraints.NotBlank;
+import lombok.Builder;
 import lombok.Getter;
 
 public class ChatRequest {
 
     @Getter
+    @Builder
     public static class ChatDto {
         private boolean guide;
         @NotBlank(message = "채팅을 입력해주세요.")
diff --git a/src/test/java/corecord/dev/chat/repository/ChatRepositoryTest.java b/src/test/java/corecord/dev/chat/repository/ChatRepositoryTest.java
new file mode 100644
index 0000000..671333f
--- /dev/null
+++ b/src/test/java/corecord/dev/chat/repository/ChatRepositoryTest.java
@@ -0,0 +1,108 @@
+package corecord.dev.chat.repository;
+
+import corecord.dev.domain.chat.entity.Chat;
+import corecord.dev.domain.chat.entity.ChatRoom;
+import corecord.dev.domain.chat.repository.ChatRepository;
+import corecord.dev.domain.chat.repository.ChatRoomRepository;
+import corecord.dev.domain.user.entity.User;
+import corecord.dev.domain.user.repository.UserRepository;
+import jakarta.persistence.EntityManager;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.autoconfigure.jdbc.AutoConfigureTestDatabase;
+import org.springframework.boot.test.autoconfigure.orm.jpa.DataJpaTest;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+@DataJpaTest
+@Transactional
+@AutoConfigureTestDatabase(replace = AutoConfigureTestDatabase.Replace.NONE)
+class ChatRepositoryTest {
+
+    @Autowired
+    ChatRepository chatRepository;
+
+    @Autowired
+    ChatRoomRepository chatRoomRepository;
+
+    @Autowired
+    UserRepository userRepository;
+
+    @Autowired
+    EntityManager entityManager;
+
+    @Test
+    @DisplayName("채팅방 ID로 채팅 삭제 테스트")
+    void deleteByChatRoomId() {
+        // Given
+        User user = createTestUser();
+        ChatRoom chatRoom = createTestChatRoom(user);
+
+        createTestChat(chatRoom, "First message");
+        createTestChat(chatRoom, "Second message");
+
+        List<Chat> chatsBeforeDelete = chatRepository.findByChatRoomOrderByChatId(chatRoom);
+        assertEquals(2, chatsBeforeDelete.size());
+
+        // When
+        chatRepository.deleteByChatRoomId(chatRoom.getChatRoomId());
+        entityManager.flush();
+
+        // Then
+        List<Chat> chatsAfterDelete = chatRepository.findByChatRoomOrderByChatId(chatRoom);
+        assertTrue(chatsAfterDelete.isEmpty());
+    }
+
+    @Test
+    @DisplayName("채팅방에 속한 채팅 조회 테스트")
+    void findByChatRoomOrderByChatId() {
+        // Given
+        User user = createTestUser();
+        ChatRoom chatRoom = createTestChatRoom(user);
+
+        createTestChat(chatRoom, "First message");
+        createTestChat(chatRoom, "Second message");
+        createTestChat(chatRoom, "Third message");
+
+        // When
+        List<Chat> chats = chatRepository.findByChatRoomOrderByChatId(chatRoom);
+
+        // Then
+        assertEquals(3, chats.size());
+        assertEquals("First message", chats.get(0).getContent());
+        assertEquals("Second message", chats.get(1).getContent());
+        assertEquals("Third message", chats.get(2).getContent());
+    }
+
+    private User createTestUser() {
+        // 사용자 저장 시 persist 호출
+        User user = User.builder()
+                .providerId("testProvider")
+                .nickName("TestUser")
+                .status(corecord.dev.domain.user.entity.Status.UNIVERSITY_STUDENT)
+                .build();
+        userRepository.save(user);
+        return user;
+    }
+
+    private ChatRoom createTestChatRoom(User user) {
+        ChatRoom chatRoom = ChatRoom.builder()
+                .user(user)
+                .build();
+        chatRoomRepository.save(chatRoom);
+        return chatRoom;
+    }
+
+    private void createTestChat(ChatRoom chatRoom, String content) {
+        Chat chat = Chat.builder()
+                .author(1)
+                .content(content)
+                .chatRoom(chatRoom)
+                .build();
+        chatRepository.save(chat);
+    }
+}
diff --git a/src/test/java/corecord/dev/chat/repository/ChatRoomRepositoryTest.java b/src/test/java/corecord/dev/chat/repository/ChatRoomRepositoryTest.java
new file mode 100644
index 0000000..6b3528c
--- /dev/null
+++ b/src/test/java/corecord/dev/chat/repository/ChatRoomRepositoryTest.java
@@ -0,0 +1,77 @@
+package corecord.dev.chat.repository;
+
+import corecord.dev.domain.chat.entity.ChatRoom;
+import corecord.dev.domain.chat.repository.ChatRoomRepository;
+import corecord.dev.domain.user.entity.Status;
+import corecord.dev.domain.user.entity.User;
+import corecord.dev.domain.user.repository.UserRepository;
+import jakarta.persistence.EntityManager;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.autoconfigure.jdbc.AutoConfigureTestDatabase;
+import org.springframework.boot.test.autoconfigure.orm.jpa.DataJpaTest;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.util.Optional;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+@DataJpaTest
+@Transactional
+@AutoConfigureTestDatabase(replace = AutoConfigureTestDatabase.Replace.NONE)
+class ChatRoomRepositoryTest {
+
+    @Autowired
+    ChatRoomRepository chatRoomRepository;
+
+    @Autowired
+    UserRepository userRepository;
+
+    @Autowired
+    EntityManager entityManager;
+
+    @Test
+    @DisplayName("ChatRoom ID와 User로 채팅방 조회 테스트")
+    void findByChatRoomIdAndUser() {
+        // Given
+        User user = createTestUser();
+        ChatRoom chatRoom = createTestChatRoom(user);
+
+        // When
+        Optional<ChatRoom> foundChatRoom = chatRoomRepository.findByChatRoomIdAndUser(chatRoom.getChatRoomId(), user);
+
+        // Then
+        assertTrue(foundChatRoom.isPresent());
+        assertEquals(foundChatRoom.get().getUser(), user);
+    }
+
+    @Test
+    @DisplayName("존재하지 않는 채팅방 조회 테스트")
+    void findByChatRoomIdAndUser_NotFound() {
+        // Given
+        User user = createTestUser();
+
+        // When
+        Optional<ChatRoom> foundChatRoom = chatRoomRepository.findByChatRoomIdAndUser(999L, user);
+
+        // Then
+        assertFalse(foundChatRoom.isPresent());
+    }
+
+    private User createTestUser() {
+        User user = User.builder()
+                .providerId("testProvider")
+                .nickName("TestUser")
+                .status(Status.UNIVERSITY_STUDENT)
+                .build();
+        return userRepository.save(user);
+    }
+
+    private ChatRoom createTestChatRoom(User user) {
+        ChatRoom chatRoom = ChatRoom.builder()
+                .user(user)
+                .build();
+        return chatRoomRepository.save(chatRoom);
+    }
+}
diff --git a/src/test/java/corecord/dev/chat/service/ChatServiceTest.java b/src/test/java/corecord/dev/chat/service/ChatServiceTest.java
new file mode 100644
index 0000000..71e209e
--- /dev/null
+++ b/src/test/java/corecord/dev/chat/service/ChatServiceTest.java
@@ -0,0 +1,325 @@
+package corecord.dev.chat.service;
+
+import corecord.dev.domain.chat.dto.request.ChatRequest;
+import corecord.dev.domain.chat.dto.response.ChatResponse;
+import corecord.dev.domain.chat.entity.Chat;
+import corecord.dev.domain.chat.entity.ChatRoom;
+import corecord.dev.domain.chat.exception.model.ChatException;
+import corecord.dev.domain.chat.repository.ChatRepository;
+import corecord.dev.domain.chat.repository.ChatRoomRepository;
+import corecord.dev.domain.chat.service.ChatService;
+import corecord.dev.domain.chat.service.ClovaRequest;
+import corecord.dev.domain.chat.service.ClovaService;
+import corecord.dev.domain.user.entity.Status;
+import corecord.dev.domain.user.entity.User;
+import corecord.dev.domain.user.repository.UserRepository;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Nested;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.InjectMocks;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+
+import java.lang.reflect.Field;
+import java.time.LocalDateTime;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Optional;
+
+import static org.junit.jupiter.api.Assertions.*;
+import static org.mockito.Mockito.*;
+
+@ExtendWith(MockitoExtension.class)
+class ChatServiceTest {
+
+    @InjectMocks
+    private ChatService chatService;
+
+    @Mock
+    private ChatRoomRepository chatRoomRepository;
+
+    @Mock
+    private ChatRepository chatRepository;
+
+    @Mock
+    private UserRepository userRepository;
+
+    @Mock
+    private ClovaService clovaService;
+
+    private User user;
+
+    private ChatRoom chatRoom;
+
+    @BeforeEach
+    void setUp() {
+        user = createTestUser();
+        chatRoom = createTestChatRoom();
+
+    }
+
+    @Test
+    @DisplayName("채팅방 생성 테스트")
+    void createChatRoom() {
+        // Given
+        when(userRepository.findById(user.getUserId())).thenReturn(Optional.of(user));
+
+        // When
+        ChatResponse.ChatRoomDto result = chatService.createChatRoom(user.getUserId());
+
+        // Then
+        verify(chatRoomRepository).save(any(ChatRoom.class));
+        verify(chatRepository).save(any(Chat.class));
+        assertEquals(result.getFirstChat(), "안녕하세요! testUser님\n오늘은 어떤 경험을 했나요?\n저와 함께 정리해보아요!");
+    }
+
+    @Test
+    @DisplayName("채팅 조회 테스트")
+    void getChatList() throws NoSuchFieldException, IllegalAccessException {
+        // Given
+        Chat userChat = createTestChat("userChat", 1);
+        Chat aiChat = createTestChat("aiChat", 0);
+
+
+        when(chatRepository.findByChatRoomOrderByChatId(chatRoom)).thenReturn(List.of(userChat, aiChat));
+        when(userRepository.findById(user.getUserId())).thenReturn(Optional.of(user));
+        when(chatRoomRepository.findByChatRoomIdAndUser(chatRoom.getChatRoomId(), user)).thenReturn(Optional.of(chatRoom));
+
+        // When
+        ChatResponse.ChatListDto result = chatService.getChatList(user.getUserId(), chatRoom.getChatRoomId());
+
+        // Then
+        assertEquals(result.getChats().size(), 2);
+        assertEquals(result.getChats().get(0).getContent(), "userChat");
+        assertEquals(result.getChats().get(1).getContent(), "aiChat");
+    }
+
+    @Nested
+    @DisplayName("채팅 생성하기 테스트")
+    class ChatServiceAiResponseTests {
+
+        @Test
+        @DisplayName("가이드 호출 시")
+        void createChatWithGuide() {
+            // Given
+            ChatRequest.ChatDto request = ChatRequest.ChatDto.builder()
+                    .guide(true)
+                    .content("어떤 경험을 말해야 할지 모르겠어요.")
+                    .build();
+
+            when(userRepository.findById(user.getUserId())).thenReturn(Optional.of(user));
+            when(chatRoomRepository.findByChatRoomIdAndUser(chatRoom.getChatRoomId(), user)).thenReturn(Optional.of(chatRoom));
+
+            // When
+            ChatResponse.ChatsDto result = chatService.createChat(
+                    user.getUserId(),
+                    chatRoom.getChatRoomId(),
+                    request
+            );
+
+            // Then
+            verify(chatRepository, times(3)).save(any(Chat.class)); // 사용자 입력 1개, 가이드 2개
+            assertEquals(result.getChats().size(), 2); // Guide 메시지는 두 개 생성
+            assertEquals(result.getChats().get(0).getContent(), "걱정 마세요!\n저와 대화하다 보면 경험이 정리될 거예요\uD83D\uDCDD");
+            assertEquals(result.getChats().get(1).getContent(), "오늘은 어떤 경험을 했나요?\n상황과 해결한 문제를 말해주세요!");
+        }
+
+        @Test
+        @DisplayName("AI 응답 성공 시")
+        void createChatWithSuccess() {
+            // Given
+            ChatRequest.ChatDto request = ChatRequest.ChatDto.builder()
+                    .content("테스트 입력")
+                    .build();
+
+            when(userRepository.findById(user.getUserId())).thenReturn(Optional.of(user));
+            when(chatRoomRepository.findByChatRoomIdAndUser(chatRoom.getChatRoomId(), user)).thenReturn(Optional.of(chatRoom));
+            when(chatRepository.save(any(Chat.class))).thenAnswer(invocation -> invocation.getArgument(0)); // 저장된 Chat 객체 반환
+            when(clovaService.generateAiResponse(any(ClovaRequest.class))).thenReturn("AI의 예상 응답");
+
+            // When
+            ChatResponse.ChatsDto result = chatService.createChat(
+                    user.getUserId(),
+                    chatRoom.getChatRoomId(),
+                    request
+            );
+
+            // Then
+            verify(chatRepository, times(2)).save(any(Chat.class)); // 사용자 입력 1개, AI 응답 1개
+            assertEquals(result.getChats().size(), 1);
+            assertEquals(result.getChats().getFirst().getContent(), "AI의 예상 응답");
+        }
+    }
+
+    @Nested
+    @DisplayName("채팅 요약 정보 생성 테스트")
+    class ChatSummaryTests {
+
+        @Test
+        @DisplayName("AI 응답 성공 시")
+        void validAiResponse() throws NoSuchFieldException, IllegalAccessException {
+            // Given
+            List<Chat> chatList = List.of(
+                    createTestChat("userChat1", 1),
+                    createTestChat("aiChat1", 0),
+                    createTestChat("userChat2", 1)
+            );
+
+            when(userRepository.findById(user.getUserId())).thenReturn(Optional.of(user));
+            when(chatRoomRepository.findByChatRoomIdAndUser(chatRoom.getChatRoomId(), user)).thenReturn(Optional.of(chatRoom));
+            when(chatRepository.findByChatRoomOrderByChatId(chatRoom)).thenReturn(chatList);
+            when(clovaService.generateAiResponse(any(ClovaRequest.class)))
+                    .thenReturn("{\"title\":\"요약 제목\",\"content\":\"요약 내용\"}");
+
+            // When
+            ChatResponse.ChatSummaryDto result = chatService.getChatSummary(user.getUserId(), chatRoom.getChatRoomId());
+
+            // Then
+            assertEquals(result.getTitle(), "요약 제목");
+            assertEquals(result.getContent(), "요약 내용");
+        }
+
+        @Test
+        @DisplayName("AI 응답이 빈 경우")
+        void emptyAiResponse() throws NoSuchFieldException, IllegalAccessException {
+            // Given
+            List<Chat> chatList = List.of(
+                    createTestChat("userChat1", 1),
+                    createTestChat("aiChat1", 0)
+            );
+
+            when(userRepository.findById(user.getUserId())).thenReturn(Optional.of(user));
+            when(chatRoomRepository.findByChatRoomIdAndUser(chatRoom.getChatRoomId(), user)).thenReturn(Optional.of(chatRoom));
+            when(chatRepository.findByChatRoomOrderByChatId(chatRoom)).thenReturn(chatList);
+            when(clovaService.generateAiResponse(any(ClovaRequest.class)))
+                    .thenReturn("{\"title\":\"\",\"content\":\"\"}"); // 빈 응답
+
+            // When & Then
+            assertThrows(ChatException.class, () -> chatService.getChatSummary(user.getUserId(), chatRoom.getChatRoomId()));
+        }
+
+        @Test
+        @DisplayName("AI 응답이 긴 경우 예외 발생 (제목 50자 초과)")
+        void longAiTitle() throws NoSuchFieldException, IllegalAccessException {
+            // Given
+            List<Chat> chatList = List.of(
+                    createTestChat("userChat1", 1),
+                    createTestChat("aiChat1", 0)
+            );
+
+            String longTitle = "a".repeat(51); // 51자 제목 생성
+            when(userRepository.findById(user.getUserId())).thenReturn(Optional.of(user));
+            when(chatRoomRepository.findByChatRoomIdAndUser(chatRoom.getChatRoomId(), user)).thenReturn(Optional.of(chatRoom));
+            when(chatRepository.findByChatRoomOrderByChatId(chatRoom)).thenReturn(chatList);
+            when(clovaService.generateAiResponse(any(ClovaRequest.class)))
+                    .thenReturn(String.format("{\"title\":\"%s\",\"content\":\"정상 내용\"}", longTitle)); // 50자 초과 제목
+
+            // When & Then
+            assertThrows(ChatException.class, () -> chatService.getChatSummary(user.getUserId(), chatRoom.getChatRoomId()));
+        }
+
+        @Test
+        @DisplayName("AI 응답이 긴 경우 예외 발생 (내용 500자 초과)")
+        void longAiResponse() throws NoSuchFieldException, IllegalAccessException {
+            // Given
+            List<Chat> chatList = List.of(
+                    createTestChat("userChat1", 1),
+                    createTestChat("aiChat1", 0)
+            );
+
+            String longContent = "a".repeat(501); // 501자 응답 생성
+            when(userRepository.findById(user.getUserId())).thenReturn(Optional.of(user));
+            when(chatRoomRepository.findByChatRoomIdAndUser(chatRoom.getChatRoomId(), user)).thenReturn(Optional.of(chatRoom));
+            when(chatRepository.findByChatRoomOrderByChatId(chatRoom)).thenReturn(chatList);
+            when(clovaService.generateAiResponse(any(ClovaRequest.class)))
+                    .thenReturn(String.format("{\"title\":\"정상 제목\",\"content\":\"%s\"}", longContent)); // 500자 초과 내용
+
+            // When & Then
+            assertThrows(ChatException.class, () -> chatService.getChatSummary(user.getUserId(), chatRoom.getChatRoomId()));
+        }
+    }
+
+    @Nested
+    @DisplayName("임시 채팅방 테스트")
+    class ChatTmpTests {
+
+        @Test
+        @DisplayName("저장 성공")
+        void saveChatTmp() {
+            // Given
+            when(userRepository.findById(user.getUserId())).thenReturn(Optional.of(user));
+            when(chatRoomRepository.findByChatRoomIdAndUser(chatRoom.getChatRoomId(), user)).thenReturn(Optional.of(chatRoom));
+
+            // When
+            chatService.saveChatTmp(user.getUserId(), chatRoom.getChatRoomId());
+
+            // Then
+            assertEquals(user.getTmpChat(), chatRoom.getChatRoomId());
+            verify(userRepository).findById(user.getUserId());
+        }
+
+        @Test
+        @DisplayName("이미 임시 저장된 채팅방이 있을 경우 예외 처리")
+        void saveChatTmpFailsWhenTmpChatExists() {
+            // Given
+            user.updateTmpChat(chatRoom.getChatRoomId());
+            when(userRepository.findById(user.getUserId())).thenReturn(Optional.of(user));
+            when(chatRoomRepository.findByChatRoomIdAndUser(chatRoom.getChatRoomId(), user)).thenReturn(Optional.of(chatRoom));
+
+            // When & Then
+            assertThrows(ChatException.class, () -> chatService.saveChatTmp(user.getUserId(), chatRoom.getChatRoomId()));
+        }
+
+        @Test
+        @DisplayName("조회 성공")
+        void getChatTmp() {
+            // Given
+            user.updateTmpChat(chatRoom.getChatRoomId());
+            when(userRepository.findById(user.getUserId())).thenReturn(Optional.of(user));
+
+            // When
+            ChatResponse.ChatTmpDto result = chatService.getChatTmp(user.getUserId());
+
+            // Then
+            assertEquals(result.getChatRoomId(), chatRoom.getChatRoomId());
+            assertTrue(result.isExist());
+            verify(userRepository).findById(user.getUserId());
+        }
+    }
+
+    private User createTestUser() {
+        return User.builder()
+                .userId(1L)
+                .providerId("providerId")
+                .nickName("testUser")
+                .status(Status.UNIVERSITY_STUDENT)
+                .abilities(new ArrayList<>())
+                .chatRooms(new ArrayList<>())
+                .folders(new ArrayList<>())
+                .records(new ArrayList<>())
+                .build();
+    }
+
+    private ChatRoom createTestChatRoom() {
+        return ChatRoom.builder()
+                .chatRoomId(1L)
+                .user(user)
+                .chatList(new ArrayList<>())
+                .build();
+    }
+
+    private Chat createTestChat(String content, int isSystem) throws IllegalAccessException, NoSuchFieldException {
+        Chat chat =  Chat.builder()
+                .chatId(1L)
+                .author(isSystem)
+                .content(content)
+                .chatRoom(chatRoom)
+                .build();
+        Field createdAtField = Chat.class.getSuperclass().getDeclaredField("createdAt");
+        createdAtField.setAccessible(true);
+        createdAtField.set(chat, LocalDateTime.now());
+        return chat;
+    }
+}