diff --git a/src/test/java/co/jp/app/UserServiceTest.java b/src/test/java/co/jp/app/UserServiceTest.java
new file mode 100644
index 0000000..7a41e82
--- /dev/null
+++ b/src/test/java/co/jp/app/UserServiceTest.java
@@ -0,0 +1,168 @@
+package co.jp.app;
+import static org.junit.jupiter.api.Assertions.*;
+import static org.mockito.ArgumentMatchers.*;
+import static org.mockito.Mockito.*;
+
+import java.util.Optional;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.junit.jupiter.api.function.Executable;
+import org.mockito.InjectMocks;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+import org.springframework.security.core.userdetails.UserDetails;
+import org.springframework.security.core.userdetails.UsernameNotFoundException;
+import org.springframework.security.crypto.password.PasswordEncoder;
+
+import co.jp.app.common.ResultCode;
+import co.jp.app.dto.RegistrationDto;
+import co.jp.app.entity.UserEntity;
+import co.jp.app.exception.BusinessException;
+import co.jp.app.repository.UserRepository;
+import co.jp.app.service.UserService;
+
+@ExtendWith(MockitoExtension.class)
+public class UserServiceTest {
+
+    @Mock
+    private UserRepository userRepository;
+
+    @Mock
+    private PasswordEncoder passwordEncoder;
+
+    @InjectMocks
+    private UserService userService;
+
+    private RegistrationDto registrationDto;
+    private UserEntity userEntity;
+
+    @BeforeEach
+    public void setUp() {
+        registrationDto = new RegistrationDto();
+        registrationDto.setName("Test User");
+        registrationDto.setEmail("test@example.com");
+        registrationDto.setPassword("password123");
+
+        userEntity = new UserEntity();
+        userEntity.setName("Test User");
+        userEntity.setEmail("test@example.com");
+        userEntity.setPassword("encodedPassword");
+    }
+
+    @Test
+    @DisplayName("新用户注册成功")
+    public void registerNewUser_success() throws BusinessException {
+        // Arrange
+        when(userRepository.existsByEmail(anyString())).thenReturn(false);
+        when(passwordEncoder.encode(anyString())).thenReturn("encodedPassword");
+        when(userRepository.save(any(UserEntity.class))).thenReturn(userEntity);
+
+        // Act
+        UserEntity savedUser = userService.registerNewUser(registrationDto);
+
+        // Assert
+        assertNotNull(savedUser);
+        assertEquals(userEntity.getEmail(), savedUser.getEmail());
+        assertEquals("encodedPassword", savedUser.getPassword());
+        verify(userRepository, times(1)).existsByEmail("test@example.com");
+        verify(passwordEncoder, times(1)).encode("password123");
+        verify(userRepository, times(1)).save(any(UserEntity.class));
+    }
+
+    @Test
+    @DisplayName("用户注册 - 邮箱已存在")
+    public void registerNewUser_emailAlreadyExists() {
+        // Arrange
+        when(userRepository.existsByEmail(anyString())).thenReturn(true);
+
+        // Act & Assert
+        BusinessException exception = assertThrows(BusinessException.class, new Executable() {
+            public void execute() throws Throwable {
+                userService.registerNewUser(registrationDto);
+            }
+        });
+
+        assertEquals(ResultCode.USER_EMAIL_ALREADY_EXISTS, exception.getResultCode());
+        verify(userRepository, times(1)).existsByEmail("test@example.com");
+        verify(passwordEncoder, never()).encode(anyString());
+        verify(userRepository, never()).save(any(UserEntity.class));
+    }
+
+    @Test
+    @DisplayName("用户注册 - 密码过短")
+    public void registerNewUser_passwordTooShort() {
+        // Arrange
+        registrationDto.setPassword("123"); // 设置一个短密码
+        when(userRepository.existsByEmail(anyString())).thenReturn(false);
+
+        // Act & Assert
+        BusinessException exception = assertThrows(BusinessException.class, new Executable() {
+            public void execute() throws Throwable {
+                userService.registerNewUser(registrationDto);
+            }
+        });
+
+        assertEquals(ResultCode.USER_PASSWORD_TOO_SHORT, exception.getResultCode());
+        verify(userRepository, times(1)).existsByEmail("test@example.com");
+        verify(passwordEncoder, never()).encode(anyString());
+        verify(userRepository, never()).save(any(UserEntity.class));
+    }
+    
+    @Test
+    @DisplayName("用户注册 - 密码为null")
+    public void registerNewUser_passwordIsNull() {
+        // Arrange
+        registrationDto.setPassword(null); // 设置密码为null
+        when(userRepository.existsByEmail(anyString())).thenReturn(false);
+
+        // Act & Assert
+        BusinessException exception = assertThrows(BusinessException.class, new Executable() {
+            public void execute() throws Throwable {
+                userService.registerNewUser(registrationDto);
+            }
+        });
+
+        assertEquals(ResultCode.USER_PASSWORD_TOO_SHORT, exception.getResultCode());
+        verify(userRepository, times(1)).existsByEmail("test@example.com");
+        verify(passwordEncoder, never()).encode(anyString());
+        verify(userRepository, never()).save(any(UserEntity.class));
+    }
+
+    @Test
+    @DisplayName("通过邮箱加载用户 - 用户存在")
+    public void loadUserByUsername_userFound() {
+        // Arrange
+        when(userRepository.findByEmail(anyString())).thenReturn(Optional.of(userEntity));
+
+        // Act
+        UserDetails userDetails = userService.loadUserByUsername("test@example.com");
+
+        // Assert
+        assertNotNull(userDetails);
+        assertEquals(userEntity.getEmail(), userDetails.getUsername());
+        assertEquals(userEntity.getPassword(), userDetails.getPassword());
+        assertTrue(userDetails.getAuthorities().stream()
+                .anyMatch(grantedAuthority -> grantedAuthority.getAuthority().equals("ROLE_USER")));
+        verify(userRepository, times(1)).findByEmail("test@example.com");
+    }
+
+    @Test
+    @DisplayName("通过邮箱加载用户 - 用户不存在")
+    public void loadUserByUsername_userNotFound() {
+        // Arrange
+        when(userRepository.findByEmail(anyString())).thenReturn(Optional.empty());
+
+        // Act & Assert
+        UsernameNotFoundException exception = assertThrows(UsernameNotFoundException.class, new Executable() {
+            public void execute() throws Throwable {
+                userService.loadUserByUsername("unknown@example.com");
+            }
+        });
+
+        assertEquals("unknown@example.com not found", exception.getMessage());
+        verify(userRepository, times(1)).findByEmail("unknown@example.com");
+    }
+}
\ No newline at end of file
diff --git a/src/test/java/co/jp/app/UserServiceTest1.java b/src/test/java/co/jp/app/UserServiceTest1.java
new file mode 100644
index 0000000..192cc47
--- /dev/null
+++ b/src/test/java/co/jp/app/UserServiceTest1.java
@@ -0,0 +1,70 @@
+package co.jp.app;
+
+import static org.junit.jupiter.api.Assertions.*;
+import static org.mockito.ArgumentMatchers.*;
+import static org.mockito.Mockito.*;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.DisplayName;
+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.security.crypto.password.PasswordEncoder;
+
+import co.jp.app.dto.RegistrationDto;
+import co.jp.app.entity.UserEntity;
+import co.jp.app.exception.BusinessException;
+import co.jp.app.repository.UserRepository;
+import co.jp.app.service.UserService;
+
+@ExtendWith(MockitoExtension.class)
+public class UserServiceTest1 {
+
+	@Mock
+	private UserRepository userRepository;
+
+	@Mock
+	private PasswordEncoder passwordEncoder;
+
+	@InjectMocks
+	private UserService userService;
+
+	private RegistrationDto registrationDto;
+	private UserEntity userEntity;
+
+	@BeforeEach
+	public void setUp() {
+		registrationDto = new RegistrationDto();
+		registrationDto.setName("Test User");
+		registrationDto.setEmail("test@example.com");
+		registrationDto.setPassword("password123");
+
+		userEntity = new UserEntity();
+		userEntity.setName("Test User");
+		userEntity.setEmail("test@example.com");
+		userEntity.setPassword("encodedPassword");
+	}
+
+	@Test
+	@DisplayName("新用户注册成功")
+	public void registerNewUser_success() throws BusinessException {
+		// Arrange
+		when(userRepository.existsByEmail(anyString())).thenReturn(false);
+		when(passwordEncoder.encode(anyString())).thenReturn("encodedPassword");
+		when(userRepository.save(any(UserEntity.class))).thenReturn(userEntity);
+
+		// Act
+		UserEntity savedUser = userService.registerNewUser(registrationDto);
+
+		// Assert
+		assertNotNull(savedUser);
+		assertEquals(userEntity.getEmail(), savedUser.getEmail());
+		assertEquals("encodedPassword", savedUser.getPassword());
+		verify(userRepository, times(1)).existsByEmail("test@example.com");
+		verify(passwordEncoder, times(1)).encode("password123");
+		verify(userRepository, times(1)).save(any(UserEntity.class));
+	}
+
+}
diff --git a/target/test-classes/co/jp/app/UserServiceTest$1.class b/target/test-classes/co/jp/app/UserServiceTest$1.class
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