diff --git a/LifeLog/LifeLog/ServerAPI.m b/LifeLog/LifeLog/ServerAPI.m
index 32144e2..d6ade05 100644
--- a/LifeLog/LifeLog/ServerAPI.m
+++ b/LifeLog/LifeLog/ServerAPI.m
@@ -350,8 +350,14 @@ NSURLSessionDataTask * searchTask;
                 }
                 
                 if ([message isEqualToString:@"Token is invalid"]) {
-                    [self performSelectorOnMainThread:@selector(checkToken) withObject:nil waitUntilDone:YES];
-                    [self requestTopWithMode:mode andDate:date CompletionHandler:completion];
+                    [self checkTokenCompletionHandler:^(NSString *token, NSError *error) {
+                        if (error == nil) {
+                            [self requestTopWithMode:mode andDate:date CompletionHandler:completion];
+                        }
+                        else {
+                            completion(nil, error);
+                        }
+                    }];
                 }
                 else {
                     NSError *errorObject = [NSError errorWithDomain:@"LifeLog_Domain" code:-1 userInfo:@{@"message":message}];
@@ -407,8 +413,14 @@ NSURLSessionDataTask * searchTask;
                 }
                 
                 if ([message isEqualToString:@"Token is invalid"]) {
-                    [self performSelectorOnMainThread:@selector(checkToken) withObject:nil waitUntilDone:YES];
-                    [self requestHomeWithMode:mode andDate:date CompletionHandler:completion];
+                    [self checkTokenCompletionHandler:^(NSString *token, NSError *error) {
+                        if (error == nil) {
+                            [self requestHomeWithMode:mode andDate:date CompletionHandler:completion];
+                        }
+                        else {
+                            completion(nil, error);
+                        }
+                    }];
                 }
                 else {
                     NSError *errorObject = [NSError errorWithDomain:@"LifeLog_Domain" code:-1 userInfo:@{@"message":message}];
@@ -447,8 +459,14 @@ NSURLSessionDataTask * searchTask;
                 }
                 
                 if ([message isEqualToString:@"Token is invalid"]) {
-                    [self performSelectorOnMainThread:@selector(checkToken) withObject:nil waitUntilDone:YES];
-                    [self requestCreateLog:mode withStep:numStep startDate:startDate endDate:endDate CompletionHandler:completion];
+                    [self checkTokenCompletionHandler:^(NSString *token, NSError *error) {
+                        if (error == nil) {
+                            [self requestCreateLog:mode withStep:numStep startDate:startDate endDate:endDate CompletionHandler:completion];
+                        }
+                        else {
+                            completion(error);
+                        }
+                    }];
                 }
                 else {
                     NSError *errorObject = [NSError errorWithDomain:@"LifeLog_Domain" code:-1 userInfo:@{@"message":message}];
@@ -506,9 +524,15 @@ NSURLSessionDataTask * searchTask;
                 }
                 
                 if ([message isEqualToString:@"Token is invalid"]) {
-                    [self performSelectorOnMainThread:@selector(checkToken) withObject:nil waitUntilDone:YES];
-                    NSString *tokenNew = [[NSUserDefaults standardUserDefaults] objectForKey:kToken];
-                    [self requestHistory:tokenNew startDate:startDate endDate:endDate CompletionHandler:completion];
+                    [self checkTokenCompletionHandler:^(NSString *token, NSError *error) {
+                        if (error == nil) {
+                            NSString *tokenNew = [[NSUserDefaults standardUserDefaults] objectForKey:kToken];
+                            [self requestHistory:tokenNew startDate:startDate endDate:endDate CompletionHandler:completion];
+                        }
+                        else {
+                            completion(nil, error);
+                        }
+                    }];
                 }
                 else {
                     NSError *errorObject = [NSError errorWithDomain:@"LifeLog_Domain" code:-1 userInfo:@{@"message":message}];
@@ -576,9 +600,15 @@ NSURLSessionDataTask * searchTask;
                 }
                 
                 if ([message isEqualToString:@"Token is invalid"]) {
-                    [self performSelectorOnMainThread:@selector(checkToken) withObject:nil waitUntilDone:YES];
-                    NSString *tokenNew = [[NSUserDefaults standardUserDefaults] objectForKey:kToken];
-                    [self requestHistoryList:tokenNew startDate:startDate endDate:endDate CompletionHandler:completion];
+                    [self checkTokenCompletionHandler:^(NSString *token, NSError *error) {
+                        if (error == nil) {
+                            NSString *tokenNew = [[NSUserDefaults standardUserDefaults] objectForKey:kToken];
+                            [self requestHistoryList:tokenNew startDate:startDate endDate:endDate CompletionHandler:completion];
+                        }
+                        else {
+                            completion(nil, error);
+                        }
+                    }];
                 }
                 else {
                     NSError *errorObject = [NSError errorWithDomain:@"LifeLog_Domain" code:-1 userInfo:@{@"message":message}];
@@ -633,9 +663,15 @@ NSURLSessionDataTask * searchTask;
                 }
                 
                 if ([message isEqualToString:@"Token is invalid"]) {
-                    [self performSelectorOnMainThread:@selector(checkToken) withObject:nil waitUntilDone:YES];
-                    NSString *tokenNew = [[NSUserDefaults standardUserDefaults] objectForKey:kToken];
-                    [self requestTweetsList:tokenNew groupID:groupID withPage:page CompletionHandler:completion];
+                    [self checkTokenCompletionHandler:^(NSString *token, NSError *error) {
+                        if (error == nil) {
+                            NSString *tokenNew = [[NSUserDefaults standardUserDefaults] objectForKey:kToken];
+                            [self requestTweetsList:tokenNew groupID:groupID withPage:page CompletionHandler:completion];
+                        }
+                        else {
+                            completion(nil, error);
+                        }
+                    }];
                 }
                 else {
                     NSError *errorObject = [NSError errorWithDomain:@"LifeLog_Domain" code:-1 userInfo:@{@"message":message}];
@@ -741,9 +777,15 @@ NSURLSessionDataTask * searchTask;
                 }
                 
                 if ([message isEqualToString:@"Token is invalid"]) {
-                    [self performSelectorOnMainThread:@selector(checkToken) withObject:nil waitUntilDone:YES];
-                    NSString *tokenNew = [[NSUserDefaults standardUserDefaults] objectForKey:kToken];
-                    [self requestCreateGroup:tokenNew withGroup:group CompletionHandler:completion];
+                    [self checkTokenCompletionHandler:^(NSString *token, NSError *error) {
+                        if (error == nil) {
+                            NSString *tokenNew = [[NSUserDefaults standardUserDefaults] objectForKey:kToken];
+                            [self requestCreateGroup:tokenNew withGroup:group CompletionHandler:completion];
+                        }
+                        else {
+                            completion(nil, error);
+                        }
+                    }];
                 }
                 else {
                     NSError *errorObject = [NSError errorWithDomain:@"LifeLog_Domain" code:-1 userInfo:@{@"message":message}];
@@ -790,9 +832,15 @@ NSURLSessionDataTask * searchTask;
                 }
                 
                 if ([message isEqualToString:@"Token is invalid"]) {
-                    [self performSelectorOnMainThread:@selector(checkToken) withObject:nil waitUntilDone:YES];
-                    NSString *tokenNew = [[NSUserDefaults standardUserDefaults] objectForKey:kToken];
-                    [self getGroupDetail:tokenNew withGroupID:groupID CompletionHandler:completion];
+                    [self checkTokenCompletionHandler:^(NSString *token, NSError *error) {
+                        if (error == nil) {
+                            NSString *tokenNew = [[NSUserDefaults standardUserDefaults] objectForKey:kToken];
+                            [self getGroupDetail:tokenNew withGroupID:groupID CompletionHandler:completion];
+                        }
+                        else {
+                            completion(nil, error);
+                        }
+                    }];
                 }
                 else {
                     NSError *errorObject = [NSError errorWithDomain:@"LifeLog_Domain" code:-1 userInfo:@{@"message":message}];
@@ -843,9 +891,15 @@ NSURLSessionDataTask * searchTask;
                 }
                 
                 if ([message isEqualToString:@"Token is invalid"]) {
-                    [self performSelectorOnMainThread:@selector(checkToken) withObject:nil waitUntilDone:YES];
-                    NSString *tokenNew = [[NSUserDefaults standardUserDefaults] objectForKey:kToken];
-                    [self requestMemberList:tokenNew groupID:groupID withPage:page CompletionHandler:completion];
+                    [self checkTokenCompletionHandler:^(NSString *token, NSError *error) {
+                        if (error == nil) {
+                            NSString *tokenNew = [[NSUserDefaults standardUserDefaults] objectForKey:kToken];
+                            [self requestMemberList:tokenNew groupID:groupID withPage:page CompletionHandler:completion];
+                        }
+                        else {
+                            completion(nil, error);
+                        }
+                    }];
                 }
                 else {
                     NSError *errorObject = [NSError errorWithDomain:@"LifeLog_Domain" code:-1 userInfo:@{@"message":message}];
@@ -886,9 +940,15 @@ NSURLSessionDataTask * searchTask;
             else {
                 NSString *message = dataResult[@"message"];
                 if ([message isEqualToString:@"Token is invalid"]) {
-                    [self performSelectorOnMainThread:@selector(checkToken) withObject:nil waitUntilDone:YES];
-                    NSString *tokenNew = [[NSUserDefaults standardUserDefaults] objectForKey:kToken];
-                    [self requestJoinGroup:tokenNew groupID:groupID CompletionHandler:completion];
+                    [self checkTokenCompletionHandler:^(NSString *token, NSError *error) {
+                        if (error == nil) {
+                            NSString *tokenNew = [[NSUserDefaults standardUserDefaults] objectForKey:kToken];
+                            [self requestJoinGroup:tokenNew groupID:groupID CompletionHandler:completion];
+                        }
+                        else {
+                            completion(error);
+                        }
+                    }];
                 }
                 else {
                     NSError *errorObject = [NSError errorWithDomain:@"LifeLog_Domain" code:-1 userInfo:@{@"message":message}];
@@ -939,9 +999,15 @@ NSURLSessionDataTask * searchTask;
                 }
                 
                 if ([message isEqualToString:@"Token is invalid"]) {
-                    [self performSelectorOnMainThread:@selector(checkToken) withObject:nil waitUntilDone:YES];
-                    NSString *tokenNew = [[NSUserDefaults standardUserDefaults] objectForKey:kToken];
-                    [self requestGroupList:tokenNew CompletionHandler:completion];
+                    [self checkTokenCompletionHandler:^(NSString *token, NSError *error) {
+                        if (error == nil) {
+                            NSString *tokenNew = [[NSUserDefaults standardUserDefaults] objectForKey:kToken];
+                            [self requestGroupList:tokenNew CompletionHandler:completion];
+                        }
+                        else {
+                            completion(nil, error);
+                        }
+                    }];
                 }
                 else {
                     NSError *errorObject = [NSError errorWithDomain:@"LifeLog_Domain" code:-1 userInfo:@{@"message":message}];
@@ -987,9 +1053,15 @@ NSURLSessionDataTask * searchTask;
                 }
                 
                 if ([message isEqualToString:@"Token is invalid"]) {
-                    [self performSelectorOnMainThread:@selector(checkToken) withObject:nil waitUntilDone:YES];
-                    NSString *tokenNew = [[NSUserDefaults standardUserDefaults] objectForKey:kToken];
-                    [self requestRankingList:tokenNew startDate:startDate endDate:endDate mode:mode page:page CompletionHandler:completion];
+                    [self checkTokenCompletionHandler:^(NSString *token, NSError *error) {
+                        if (error == nil) {
+                            NSString *tokenNew = [[NSUserDefaults standardUserDefaults] objectForKey:kToken];
+                            [self requestRankingList:tokenNew startDate:startDate endDate:endDate mode:mode page:page CompletionHandler:completion];
+                        }
+                        else {
+                            completion(nil, error);
+                        }
+                    }];
                 }
                 else {
                     NSError *errorObject = [NSError errorWithDomain:@"LifeLog_Domain" code:-1 userInfo:@{@"message":message}];
@@ -1024,7 +1096,7 @@ NSURLSessionDataTask * searchTask;
                     completion(token, nil);
                 }
                 else {
-                    NSError *errorObject = [NSError errorWithDomain:@"LifeLog_Domain" code:-1 userInfo:@{@"message":@"Unknown Error"}];
+                    NSError *errorObject = [NSError errorWithDomain:@"LifeLog_Domain" code:-1 userInfo:@{@"message":@"refreshToken Error"}];
                     completion(nil, errorObject);
                 }
                 
@@ -1032,7 +1104,7 @@ NSURLSessionDataTask * searchTask;
             else { // status = 0 error
                 NSString *message = dataResult[@"message"];
                 if (message == nil) {
-                    message = @"Unknown error";
+                    message = @"refreshToken Error";
                 }
                 NSError *loginFaild = [NSError errorWithDomain:@"LifeLog_Domain" code:-1 userInfo:@{@"message":message}];
                 completion(nil, loginFaild);
@@ -1091,8 +1163,8 @@ NSURLSessionDataTask * searchTask;
 }
 
 #pragma mark - Private Function
-- (void) checkToken {
-    // [[NSNotificationCenter defaultCenter] postNotificationName:kNotificationToken object:nil];
+- (void) checkTokenCompletionHandler:(void (^)(NSString *, NSError *)) completion
+{
     NSData *data = [[NSUserDefaults standardUserDefaults] objectForKey:kUser];
     User *user = (User *)[NSKeyedUnarchiver unarchiveObjectWithData:data];
     if (user != nil) {
@@ -1100,10 +1172,19 @@ NSURLSessionDataTask * searchTask;
             if (error == nil) {
                 [[NSUserDefaults standardUserDefaults] setObject:token forKey:kToken];
                 [[NSUserDefaults standardUserDefaults] synchronize];
+                completion(token, nil);
+            }
+            else {
+                completion(nil, error);
             }
         }];
     }
+    else {
+        NSError *error = [NSError errorWithDomain:@"LifeLog_Domain" code:-1 userInfo:@{@"message":@"User not found"}];
+        completion(nil, error);
+    }
 }
+
 - (NSData *) _encodeDictionary: (NSDictionary *) dictionary
 {
     NSMutableArray *parts = [[NSMutableArray alloc] init];