diff --git a/request/unpacker.go b/request/unpacker.go
index 589ec37..7ed8699 100644
--- a/request/unpacker.go
+++ b/request/unpacker.go
@@ -76,29 +76,40 @@ func (u *Unpacker) parseResponse() error {
 				return fmt.Errorf("API Gateway output format error")
 			}
 		}
+	} else {
+		u.httpResponse.Body.Close()
+		err := fmt.Errorf("Response StatusCode: %d", u.httpResponse.StatusCode)
+		logger.Error(err.Error())
+		return err
 	}
 
 	return nil
 }
 
 func (u *Unpacker) parseError() error {
-
+	if u.output.IsNil() {
+		return fmt.Errorf("nil returned")
+	}
 	retCodeValue := u.output.Elem().FieldByName("RetCode")
 	messageValue := u.output.Elem().FieldByName("Message")
 
-	if !retCodeValue.Elem().IsValid() || retCodeValue.Type().String() != "*int" {
-		return fmt.Errorf("can not get retcode")
-	}
-
-	if retCodeValue.Elem().Int() != 0 {
-		if !messageValue.Elem().IsValid() || messageValue.Type().String() != "*string" {
-			return fmt.Errorf("can not get error message")
+	if retCodeValue.IsValid() && retCodeValue.Type().String() == "*int" &&
+		retCodeValue.Elem().IsValid() {
+		if retCodeValue.Elem().Int() == 0 {
+			return nil
 		}
-
-		return &errors.QingCloudError{
+		err := &errors.QingCloudError{
 			RetCode: int(retCodeValue.Elem().Int()),
-			Message: messageValue.Elem().String(),
 		}
+		if messageValue.IsValid() && messageValue.Type().String() == "*string" {
+			if messageValue.Elem().IsValid() {
+				err.Message = messageValue.Elem().String()
+			} else {
+				err.Message = "null"
+			}
+		}
+		return err
 	}
-	return nil
+
+	return fmt.Errorf("invalid retCodeValue %v returned", retCodeValue)
 }
diff --git a/request/unpacker_test.go b/request/unpacker_test.go
index 96fe17c..4848a9d 100644
--- a/request/unpacker_test.go
+++ b/request/unpacker_test.go
@@ -149,3 +149,50 @@ func TestUnpacker_UnpackHTTPRequestWithError(t *testing.T) {
 		assert.Equal(t, e.RetCode, 1400)
 	}
 }
+
+func TestUnpacker_UnpackHTTPRequestWithWrongType2(t *testing.T) {
+	type DescribeInstanceTypesOutput struct {
+		RetCode *int    `json:"ret_code" name:"ret_code"`
+		Message *string `json:"message" name:"message"`
+	}
+
+	httpResponse := &http.Response{Header: http.Header{}}
+	httpResponse.StatusCode = 200
+	httpResponse.Header.Set("Content-Type", "application/json")
+	responseString := `{
+     "message": null,
+     "ret_code":1400
+ 	}`
+	httpResponse.Body = ioutil.NopCloser(bytes.NewReader([]byte(responseString)))
+
+	output := &DescribeInstanceTypesOutput{}
+	outputValue := reflect.ValueOf(output)
+	unpacker := Unpacker{}
+	err := unpacker.UnpackHTTPRequest(&data.Operation{}, httpResponse, &outputValue)
+	if !assert.NotNil(t, err) {
+		t.FailNow()
+	}
+	println("err", err.Error())
+}
+
+func TestUnpacker_UnpackHTTPRequestWithWrongHTTPStatus(t *testing.T) {
+	type DescribeInstanceTypesOutput struct {
+		RetCode *int    `json:"ret_code" name:"ret_code"`
+		Message *string `json:"message" name:"message"`
+	}
+
+	httpResponse := &http.Response{Header: http.Header{}}
+	httpResponse.StatusCode = 500
+	httpResponse.Header.Set("Content-Type", "application/json")
+	responseString := "{}"
+	httpResponse.Body = ioutil.NopCloser(bytes.NewReader([]byte(responseString)))
+
+	output := &DescribeInstanceTypesOutput{}
+	outputValue := reflect.ValueOf(output)
+	unpacker := Unpacker{}
+	err := unpacker.UnpackHTTPRequest(&data.Operation{}, httpResponse, &outputValue)
+	if !assert.NotNil(t, err) {
+		t.FailNow()
+	}
+	println("err", err.Error())
+}