diff --git a/sdk/auth/rpc_signature_composer.go b/sdk/auth/rpc_signature_composer.go
index cbc00a9..2c32042 100644
--- a/sdk/auth/rpc_signature_composer.go
+++ b/sdk/auth/rpc_signature_composer.go
@@ -26,6 +26,7 @@ func signRpcRequest(request requests.AcsRequest, signer Signer) (err error) {
 	request.SetStringToSign(stringToSign)
 	signature := signer.Sign(stringToSign, "&")
 	request.GetQueryParams()["sign"] = signature
+	debug("grsdk sign %s", signature)
 	return
 }
 
@@ -106,7 +107,7 @@ func unsignRpcRequest(request *http.Request, signer Signer) (err error) {
 	stringToSign = strings.Replace(stringToSign, "%7E", "~", -1)
 	stringToSign = url.QueryEscape(stringToSign)
 	stringToSign = request.Method + "&%2F&" + stringToSign
-	debug("grsdk singstring %s", stringToSign)
+	debug("grsdk signstring %s", stringToSign)
 
 	if timestamp, err := strconv.ParseInt(signParams["access_time"], 10, 64); err != nil {
 		return err