diff --git a/src/main/java/demo/api/auth/AuthController.java b/src/main/java/demo/api/auth/AuthController.java
index bca81fc..e59f22c 100644
--- a/src/main/java/demo/api/auth/AuthController.java
+++ b/src/main/java/demo/api/auth/AuthController.java
@@ -4,6 +4,7 @@ import demo.api.jwt.dtos.TokenDto;
 import demo.api.user.domain.User;
 import demo.api.user.dtos.UserSignInRequest;
 import demo.api.user.dtos.UserSignUpRequest;
+import java.util.Objects;
 import lombok.RequiredArgsConstructor;
 import org.springframework.http.ResponseEntity;
 import org.springframework.stereotype.Controller;
@@ -29,7 +30,7 @@ public class AuthController {
   public String signUp(@Validated UserSignUpRequest signUpReq) throws Exception {
     User user = authService.signUp(signUpReq);
 
-    if(user.getEmail() != "") {
+    if(!Objects.isNull(user)) {
       return "redirect:/user/signIn";
     }
 
diff --git a/src/main/java/demo/api/config/SecurityConfig.java b/src/main/java/demo/api/config/SecurityConfig.java
index 577854f..8fe4972 100644
--- a/src/main/java/demo/api/config/SecurityConfig.java
+++ b/src/main/java/demo/api/config/SecurityConfig.java
@@ -45,6 +45,7 @@ public class SecurityConfig {
         .csrf().disable()
         .formLogin()
         .loginPage("/auth/signIn")
+        .usernameParameter("email")
         .defaultSuccessUrl("/")
         .failureUrl("/auth/signIn?fail=true");
 
diff --git a/src/main/java/demo/api/config/UserDetailsServiceImpl.java b/src/main/java/demo/api/config/UserDetailsServiceImpl.java
index 3bc596e..7d9bb0a 100644
--- a/src/main/java/demo/api/config/UserDetailsServiceImpl.java
+++ b/src/main/java/demo/api/config/UserDetailsServiceImpl.java
@@ -18,7 +18,7 @@ public class UserDetailsServiceImpl implements UserDetailsService {
 
   @Override
   public UserDetails loadUserByUsername(String email) throws UserNotFoundException {
-
+    System.out.println("email in loadUserByUsername = " + email);
     User user = userRepository.findByEmail(email)
         .orElseThrow(UserNotFoundException::new);
     Set<GrantedAuthority> grantedAuthorities = new HashSet<>();
diff --git a/src/main/java/demo/api/jwt/JwtTokenFilter.java b/src/main/java/demo/api/jwt/JwtTokenFilter.java
index 56bee40..446078e 100644
--- a/src/main/java/demo/api/jwt/JwtTokenFilter.java
+++ b/src/main/java/demo/api/jwt/JwtTokenFilter.java
@@ -31,7 +31,6 @@ public class JwtTokenFilter extends OncePerRequestFilter {
         SecurityContextHolder.getContext().setAuthentication(auth); // 정상 토큰이면 SecurityContext에 저장
       }
     } catch (CustomException ex) {
-      //this is very important, since it guarantees the user is not authenticated at all
       SecurityContextHolder.clearContext();
       response.sendError(ex.getHttpStatus().value(), ex.getMessage());
       return;
diff --git a/src/main/java/demo/api/user/UserController.java b/src/main/java/demo/api/user/UserController.java
index 9eebc98..eeb7f2a 100644
--- a/src/main/java/demo/api/user/UserController.java
+++ b/src/main/java/demo/api/user/UserController.java
@@ -26,6 +26,7 @@ public class UserController {
 
   @GetMapping("/profile")
   public String profile(Model model, @AuthenticationPrincipal UserDetails userDetails) {
+    System.out.println("userDetails = " + userDetails);
     if (userDetails != null) {
       User userDetail = userService.findByEmail(userDetails.getUsername())
           .orElseThrow(() -> new UserNotFoundException());