diff --git a/webapp/controller/BagController.class.php b/webapp/controller/BagController.class.php
index 66e19b1e..c18bbfce 100644
--- a/webapp/controller/BagController.class.php
+++ b/webapp/controller/BagController.class.php
@@ -60,7 +60,11 @@ class BagController extends BaseAuthedController {
             $this->_rspErr(3, $this->_getLackItemErrMsg($lackItem));
             return;
         }
-        $this->_decItems($costItems);
+
+        $isPersist = getReqVal('is_persist', 0);
+        if ($isPersist == 1) {
+            $this->_decItems($costItems);
+        }
         $this->_rspOk();
     }