diff --git a/Server/Service/NicknameChange.cs b/Server/Service/NicknameChange.cs
index 175ebad..4a54701 100644
--- a/Server/Service/NicknameChange.cs
+++ b/Server/Service/NicknameChange.cs
@@ -18,17 +18,24 @@ namespace Server.Service
             User user = Statics.userSQL.SelectUuid(req.uuid);
             string newNickname = req.newNickname;
             string regular = @"^[가-힣a-zA-Z0-9\s]*$";
+            string defaultNick = Statics.dynamicDataSQL.SelectName("defaultNick").value;
             int buy;
 
+            //만약 시스템 설정과 같은 닉네임이 온다면 중복 처리
+            if (newNickname == defaultNick)
+            {       
+                   throw new RuntimeException("Duplicate nickname", Error.errordata);
+            }
+
             //닉네임 체크
-            //if(!Regex.IsMatch(newNickname, regular) || (newNickname.Length < 2 || newNickname.Length > 16) || user.nickname == newNickname)
-            //{
-            //    //해당 데이터가 들어온다면 유저 정보와 같이 로그를 남기게 만들것
-            //    throw new RuntimeException("Nickname not allowed", Error.errordata);
-            //}
+            if (!Regex.IsMatch(newNickname, regular) || (newNickname.Length < 2 || newNickname.Length > 16) || user.nickname == newNickname)
+            {
+                //해당 데이터가 들어온다면 유저 정보와 같이 로그를 남기게 만들것
+                throw new RuntimeException("Nickname not allowed", Error.errordata);
+            }
 
             //가격 체크
-            if (user.nickname == Statics.dynamicDataSQL.SelectName("defaultNick").value)
+            if (user.nickname == defaultNick)
                 buy = 0;
             else
                 buy = int.Parse(Statics.dynamicDataSQL.SelectName("nicknameCash").value);
@@ -39,6 +46,8 @@ namespace Server.Service
                 throw new RuntimeException("Cache shortage", Error.nogold);
             }
 
+            //닉네임 중복 검사
+
             user.nickname = newNickname;
 
             SaveSQL();