diff --git a/pkg/cibot/pullrequest.go b/pkg/cibot/pullrequest.go
index ffd49b161073c8a4da31c827d0a1c0ea0fc33eb7..e93c1456682f6ebd52d19c59897bb9bbbeef8a05 100644
--- a/pkg/cibot/pullrequest.go
+++ b/pkg/cibot/pullrequest.go
@@ -58,6 +58,19 @@ func (s *Server) HandlePullRequestEvent(actionDesc string, event *gitee.PullRequ
 				}
 			}
 		}
+		// add a tag to describe the sig name of the repo.
+		sigName := s.getSigNameFromRepo(event.Repository.FullName)
+		if len(sigName) > 0{
+			addlabel := &gitee.NoteEvent{}
+			addlabel.PullRequest = event.PullRequest
+			addlabel.Repository = event.Repository
+			addlabel.Comment = &gitee.NoteHook{}
+			err = s.AddSpecifyLabelsInPulRequest(addlabel, []string{fmt.Sprintf("sig/%s", sigName)}, true)
+			if err != nil {
+				glog.Errorf("Add special label sig info failed: %v", err)
+				return
+			}
+		}
 
 		if s.Config.AutoDetectCla {
 			err = s.CheckCLAByPullRequestEvent(event)
diff --git a/pkg/cibot/sighandler.go b/pkg/cibot/sighandler.go
index b9144e74dd1d47abcc91208c78fb283e80538986..6d70c932915477cef1adb0f9a2b423daf7c64d6f 100644
--- a/pkg/cibot/sighandler.go
+++ b/pkg/cibot/sighandler.go
@@ -439,3 +439,25 @@ func (handler *SigHandler) addSigRepos(sig Sig, mapSigRepos, mapSigReposInDB map
 
 	return nil
 }
+
+// get Sig name by Repo name
+func (s *Server) getSigNameFromRepo(repoName string) (sigName string) {
+	sigName = ""
+	if len(repoName) == 0 || len(repoName) > 128 {
+		glog.Errorf("Repo name is invalid.")
+		return
+	}
+	// get sig repos from DB
+	glog.Infof("Repo name is:%s .", repoName)
+	var srs database.SigRepositories
+	err := database.DBConnection.Model(&database.SigRepositories{}).
+		Where("repo_name = ?", repoName).Find(&srs).Error
+	if err != nil {
+		glog.Errorf("unable to get sig repos: %v", err)
+		return
+	}
+	sigName = srs.Name
+	glog.Infof("end to add sig repos for %s", sigName)
+	return
+}
+