diff --git a/OSS.Common/ComUtils/StringUtil.cs b/OSS.Common/ComUtils/StringUtil.cs
index 9dd7f23..cbac304 100644
--- a/OSS.Common/ComUtils/StringUtil.cs
+++ b/OSS.Common/ComUtils/StringUtil.cs
@@ -106,8 +106,8 @@ namespace OSS.Common.ComUtils
                     throw new ArgumentOutOfRangeException("code", "the code is not from [ToCode] method !");
 
                 value <<= 5;
-                if (count == 13 && i == 12)
-                    value = value ^ (num & 0x03);     // 最高位只有两位
+                if (i == 12)
+                    value = value ^ (num & 0x0F); // 最高位只有四位
                 else
                     value = value ^ num;
                 
diff --git a/OSS.Common/OSS.Common.All.nupkg b/OSS.Common/OSS.Common.All.nupkg
index cff632f..1e2cd31 100644
Binary files a/OSS.Common/OSS.Common.All.nupkg and b/OSS.Common/OSS.Common.All.nupkg differ