diff --git a/libauth/messages.go b/libauth/messages.go
index e0d9093..b443a64 100644
--- a/libauth/messages.go
+++ b/libauth/messages.go
@@ -1,6 +1,20 @@
 package libauth
 
-var PortalError = map[string]string{
+import "fmt"
+
+type PortalError struct {
+	Code    string
+	Message string
+}
+
+func (e *PortalError) Error() string {
+	if e.Code != "" {
+		return fmt.Sprintf("%s: %s", e.Code, e.Message)
+	}
+	return e.Message
+}
+
+var portalErrorMessages = map[string]string{
 	"E3001": "流量或时长已用尽",
 	"E3002": "计费策略条件不匹配",
 	"E3003": "控制策略条件不匹配",
diff --git a/libauth/requests.go b/libauth/requests.go
index a20d6e5..01cdae8 100644
--- a/libauth/requests.go
+++ b/libauth/requests.go
@@ -261,10 +261,10 @@ func LoginLogout(username, password string, host *UrlProvider, logout bool, anot
 		err = nil
 	} else {
 		ecode, _ := loginResp["ecode"].(string)
-		if strerr, exist := PortalError[ecode]; exist {
-			err = errors.New(strerr)
+		if msg, exist := portalErrorMessages[ecode]; exist {
+			err = &PortalError{Code: ecode, Message: msg}
 		} else {
-			err = errors.New(res)
+			err = &PortalError{Code: ecode, Message: res}
 		}
 	}