diff --git a/rpc/rpchandler.go b/rpc/rpchandler.go
index d255808..fc0d670 100644
--- a/rpc/rpchandler.go
+++ b/rpc/rpchandler.go
@@ -16,14 +16,14 @@ type FuncRpcServer func() (*Server)
 var NilError = reflect.Zero(reflect.TypeOf((*error)(nil)).Elem())
 
 type RpcError string
-
+var noError RpcError
 func (e RpcError) Error() string {
 	return string(e)
 }
 
 func ConvertError(e error) RpcError{
 	if e == nil {
-		return ""
+		return noError
 	}
 
 	rpcErr := RpcError(e.Error())
diff --git a/rpc/server.go b/rpc/server.go
index 534d005..c9411ae 100644
--- a/rpc/server.go
+++ b/rpc/server.go
@@ -316,9 +316,11 @@ func (server *Server) selfNodeRpcHandlerAsyncGo(client *Client,callerRpcHandler
 				ReleaseRpcRequest(req)
 				return
 			}
-
-			pCall.Err = Err
-
+			if len(Err) == 0 {
+				pCall.Err = nil
+			}else{
+				pCall.Err = Err
+			}
 
 			if Returns!=nil {
 				pCall.Reply = Returns