diff --git a/src/main/java/the_monitor/application/service/AccountService.java b/src/main/java/the_monitor/application/service/AccountService.java
index 724b0f3..f79a9be 100644
--- a/src/main/java/the_monitor/application/service/AccountService.java
+++ b/src/main/java/the_monitor/application/service/AccountService.java
@@ -21,7 +21,7 @@ public interface AccountService {
 
     String accountSignUp(AccountSignUpRequest request);
 
-    String accountSignIn(AccountSignInRequest request, HttpServletResponse response, HttpSession session);
+    ApiResponse<String> accountSignIn(AccountSignInRequest request, HttpServletResponse response, HttpSession session);
 
     String checkEmail(String email);
 
diff --git a/src/main/java/the_monitor/application/serviceImpl/AccountServiceImpl.java b/src/main/java/the_monitor/application/serviceImpl/AccountServiceImpl.java
index d96b3e1..f098f63 100644
--- a/src/main/java/the_monitor/application/serviceImpl/AccountServiceImpl.java
+++ b/src/main/java/the_monitor/application/serviceImpl/AccountServiceImpl.java
@@ -109,12 +109,15 @@ public String accountSignUp(AccountSignUpRequest request) {
     }
 
     @Override
-    public String accountSignIn(AccountSignInRequest request, HttpServletResponse response, HttpSession session) {
-
+    public ApiResponse<String> accountSignIn(AccountSignInRequest request, HttpServletResponse response, HttpSession session) {
         Account account = accountRepository.findAccountByEmail(request.getEmail());
 
-        if (account == null) throw new ApiException(ErrorStatus._ACCOUNT_NOT_FOUND);
-        if (!account.getPassword().equals(request.getPassword())) throw new ApiException(ErrorStatus._WRONG_PASSWORD);
+        if (account == null) {
+            return ApiResponse.onCustomSuccessData("ACCOUNT404", "계정을 찾을 수 없습니다.", null); // isSuccess: true
+        }
+        if (!account.getPassword().equals(request.getPassword())) {
+            return ApiResponse.onCustomSuccessData("ACCOUNT400", "비밀번호가 일치하지 않습니다.", null); // isSuccess: true
+        }
 
         // AccessToken 발급 및 응답 헤더에 추가
         String accessToken = jwtProvider.generateAccessToken(account);
@@ -123,8 +126,7 @@ public String accountSignIn(AccountSignInRequest request, HttpServletResponse re
         // RefreshToken 발급 및 세션에 저장
         jwtProvider.storeRefreshTokenInSession(account, session);
 
-        return "로그인 성공";
-
+        return ApiResponse.onSuccessData("로그인 성공", accessToken);
     }
 
     @Override
diff --git a/src/main/java/the_monitor/common/ApiResponse.java b/src/main/java/the_monitor/common/ApiResponse.java
index 190a58b..617da4e 100644
--- a/src/main/java/the_monitor/common/ApiResponse.java
+++ b/src/main/java/the_monitor/common/ApiResponse.java
@@ -47,6 +47,10 @@ public static <T> ApiResponse<T> of(BaseCode code, T result) {
 
     }
 
+    public static <T> ApiResponse<T> onCustomSuccessData(String code, String message, T result) {
+        return new ApiResponse<>(true, code, message, result);
+    }
+
     public static <T> ApiResponse<T> onSuccess(String message) {
 
         return new ApiResponse<>(true, SuccessStatus._OK.getCode(),
@@ -68,4 +72,6 @@ public static <T> ApiResponse<T> onFailure(String code, String message, T data)
 
     }
 
+
+
 }
\ No newline at end of file
diff --git a/src/main/java/the_monitor/common/Config/WebConfig.java b/src/main/java/the_monitor/common/Config/WebConfig.java
index a52afb3..d7b12ab 100644
--- a/src/main/java/the_monitor/common/Config/WebConfig.java
+++ b/src/main/java/the_monitor/common/Config/WebConfig.java
@@ -23,6 +23,7 @@ public void addCorsMappings(CorsRegistry registry) {
         registry.addMapping("/**")
                 .allowedOrigins("https://the-monitor.o-r.kr",
                         "http://the-monitor.o-r.kr",
+                        "https://the-monitor.vercel.app/",
                         "http://localhost:5173",
                         "http://localhost:8080")
                 .allowedMethods("*")
diff --git a/src/main/java/the_monitor/presentation/AccountController.java b/src/main/java/the_monitor/presentation/AccountController.java
index 00b6a12..d453c3f 100644
--- a/src/main/java/the_monitor/presentation/AccountController.java
+++ b/src/main/java/the_monitor/presentation/AccountController.java
@@ -52,8 +52,7 @@ public ApiResponse<String> createAccount(@RequestBody @Valid AccountSignUpReques
     @PostMapping("/signIn")
     public ApiResponse<String> Login(@RequestBody @Valid AccountSignInRequest request, HttpServletResponse response, HttpSession session) {
 
-        return ApiResponse.onSuccess(accountService.accountSignIn(request, response, session));
-
+        return accountService.accountSignIn(request, response, session);
     }
 
     @Operation(summary = "토큰 유효성 검사", description = "토큰 유효성 검사")