diff --git a/Assets/YooAsset/Samples~/Extension Sample/Runtime/CopyBuildinManifestOperation.cs b/Assets/YooAsset/Samples~/Extension Sample/Runtime/CopyBuildinManifestOperation.cs
index d3b35e0a..65bb91d5 100644
--- a/Assets/YooAsset/Samples~/Extension Sample/Runtime/CopyBuildinManifestOperation.cs	
+++ b/Assets/YooAsset/Samples~/Extension Sample/Runtime/CopyBuildinManifestOperation.cs	
@@ -2,8 +2,6 @@
 using System.Collections;
 using System.Collections.Generic;
 using System.IO;
-using System.Security.Policy;
-using UnityEngine;
 using YooAsset;
 
 /// <summary>