diff --git a/src/main/java/com/specialwarriors/conal/user/controller/UserController.java b/src/main/java/com/specialwarriors/conal/user/controller/UserController.java
index e97aa24..9b3284c 100644
--- a/src/main/java/com/specialwarriors/conal/user/controller/UserController.java
+++ b/src/main/java/com/specialwarriors/conal/user/controller/UserController.java
@@ -32,7 +32,7 @@ public String index() {
     @GetMapping("/home")
     public String home(Model model, @SessionAttribute("userId") Long userId) {
 
-        User user = userService.getUserByUserId(userId);
+        User user = userService.findById(userId);
         GithubRepoPageResponse response = githubRepoService.getGithubRepoInfos(userId, 0);
 
         model.addAttribute("repositories", response); // 레포지토리 리스트
@@ -57,7 +57,7 @@ public String loginFailure() {
     @GetMapping("/mypage")
     public String myPage(Model model, @SessionAttribute("userId") Long userId) {
 
-        User user = userService.getUserByUserId(userId);
+        User user = userService.findById(userId);
         model.addAttribute("avatarUrl", user.getAvatarUrl());
         model.addAttribute("username", user.getUsername());
 
@@ -68,7 +68,7 @@ public String myPage(Model model, @SessionAttribute("userId") Long userId) {
     public String deleteUser(HttpServletRequest request, @SessionAttribute("userId") Long userId) {
 
         sessionManager.clearSession(request);
-        userService.deleteUser(userId);
+        userService.deleteById(userId);
 
         return "user/delete-success";
     }
diff --git a/src/main/java/com/specialwarriors/conal/user/service/UserService.java b/src/main/java/com/specialwarriors/conal/user/service/UserService.java
index 6298bf0..e2bdf59 100644
--- a/src/main/java/com/specialwarriors/conal/user/service/UserService.java
+++ b/src/main/java/com/specialwarriors/conal/user/service/UserService.java
@@ -24,14 +24,14 @@ public class UserService {
     private final RedisTemplate<String, String> redisTemplate;
     private final GithubOAuth2WebClient githubOAuth2WebClient;
 
-    public User getUserByUserId(Long userId) {
+    public User findById(Long userId) {
 
         return userRepository.findById(userId)
                 .orElseThrow(() -> new GeneralException(UserException.USER_NOT_FOUND));
     }
 
     @Transactional
-    public void deleteUser(Long userId) {
+    public void deleteById(Long userId) {
 
         User user = userRepository.findById(userId)
                 .orElseThrow(() -> new GeneralException(UserException.USER_NOT_FOUND));
diff --git a/src/test/java/com/specialwarriors/conal/UserServiceTest.java b/src/test/java/com/specialwarriors/conal/UserServiceTest.java
new file mode 100644
index 0000000..884ede2
--- /dev/null
+++ b/src/test/java/com/specialwarriors/conal/UserServiceTest.java
@@ -0,0 +1,137 @@
+package com.specialwarriors.conal;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.mockito.BDDMockito.given;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+
+import com.specialwarriors.conal.common.auth.oauth.GithubOAuth2WebClient;
+import com.specialwarriors.conal.common.exception.GeneralException;
+import com.specialwarriors.conal.github_repo.repository.GithubRepoRepository;
+import com.specialwarriors.conal.notification.repository.NotificationAgreementRepository;
+import com.specialwarriors.conal.user.domain.User;
+import com.specialwarriors.conal.user.exception.UserException;
+import com.specialwarriors.conal.user.repository.UserRepository;
+import com.specialwarriors.conal.user.service.UserService;
+import java.util.Optional;
+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 org.springframework.data.redis.core.RedisTemplate;
+import org.springframework.data.redis.core.ValueOperations;
+
+@ExtendWith(MockitoExtension.class)
+public class UserServiceTest {
+
+    @Mock
+    private UserRepository userRepository;
+
+    @Mock
+    private RedisTemplate<String, String> redisTemplate;
+
+    @Mock
+    private GithubOAuth2WebClient githubOAuth2WebClient;
+
+    @Mock
+    private GithubRepoRepository githubRepoRepository;
+
+    @Mock
+    private NotificationAgreementRepository notificationAgreementRepository;
+    
+    @InjectMocks
+    private UserService userService;
+
+    private User mockUser;
+
+    @BeforeEach
+    void setUp() {
+        mockUser = new User(1, "홍길동", "honggildong@gmail.com");
+    }
+
+    @Nested
+    @DisplayName("유저 아이디로 사용자를 조회할 때")
+    class FindUserByIdTest {
+
+        @Test
+        @DisplayName("성공한다")
+        void success() {
+
+            // given
+            long userId = 1L;
+            given(userRepository.findById(userId)).willReturn(Optional.of(mockUser));
+
+            // when
+            User result = userService.findById(userId);
+
+            // then
+            assertThat(result).isEqualTo(mockUser);
+            verify(userRepository).findById(userId);
+        }
+
+        @Test
+        @DisplayName("시용자가 존재하지 않으면 예외를 던진다")
+        void throwsExceptionWhenUserNotFoundById() {
+
+            // given
+            long userId = 1L;
+            given(userRepository.findById(userId)).willReturn(Optional.empty());
+
+            // when, then
+            assertThatThrownBy(() -> userService.findById(userId))
+                    .isInstanceOf(GeneralException.class)
+                    .extracting("exception")
+                    .isEqualTo(UserException.USER_NOT_FOUND);
+        }
+    }
+
+    @Nested
+    @DisplayName("사용자를 삭제할 때")
+    class DeleteUserTest {
+
+        @Test
+        @DisplayName("깃허브 토큰과 세션을 삭제한다")
+        void deletesGithubTokenAndSessionWhenUserIsDeleted() {
+
+            // given
+            long userId = 1L;
+            String githubTokenKey = "github:token:1";
+            String githubTokenValue = "fake-access-token";
+
+            given(userRepository.findById(userId)).willReturn(Optional.of(mockUser));
+
+            ValueOperations<String, String> ops = mock(ValueOperations.class);
+            given(redisTemplate.opsForValue()).willReturn(ops);
+            given(ops.get(githubTokenKey)).willReturn(githubTokenValue);
+
+            // when
+            userService.deleteById(userId);
+
+            // then
+            verify(githubOAuth2WebClient).unlink(githubTokenValue);
+            verify(redisTemplate).unlink(githubTokenKey);
+            verify(userRepository).deleteById(userId);
+        }
+
+        @Test
+        @DisplayName("사용자가 존재하지 않으면 예외를 던진다")
+        void throwsExceptionWhenDeletingNonexistentUser() {
+
+            // given
+            long userId = 1L;
+            given(userRepository.findById(userId)).willReturn(Optional.empty());
+
+            // when, then
+            assertThatThrownBy(() -> userService.deleteById(userId))
+                    .isInstanceOf(GeneralException.class)
+                    .extracting("exception")
+                    .isEqualTo(UserException.USER_NOT_FOUND);
+        }
+    }
+
+}