diff --git a/module/gitlab/model.php b/module/gitlab/model.php
index 46415d56b0..0a22c5f143 100644
--- a/module/gitlab/model.php
+++ b/module/gitlab/model.php
@@ -863,6 +863,37 @@ class gitlabModel extends model
         return true;
     }
 
+    /**
+     * Delete project relation.
+     *
+     * condition: when user deleting a repo. 
+     * 
+     * @param  int    $repoID 
+     * @access public
+     * @return void
+     */
+    public function deleteProjectRelation($repoID)
+    {
+        $repo = $this->dao->select('product,path as gitlabProjectID,client as gitlabID')->from(TABLE_REPO)
+                     ->where('id')->eq($repoID)
+                     ->andWhere('deleted')->eq(0)
+                     ->fetch();
+        if(empty($repo)) return false;
+
+        $productIDList  = explode(',', $repo->product);
+        foreach($productIDList as $product)
+        {
+            $this->dao->delete()->from(TABLE_RELATION)
+                 ->where('product')->eq($product)
+                 ->andWhere('AType')->eq('gitlab')
+                 ->andWhere('BType')->eq('gitlabProject')
+                 ->andWhere('relation')->eq('interrated')
+                 ->andWhere('AID')->eq($repo->gitlabID)
+                 ->andWhere('BID')->eq($repo->gitlabProjectID)
+                 ->exec();
+        }
+    }
+
     /**
      * Create webhook for zentao.
      * 
diff --git a/module/repo/control.php b/module/repo/control.php
index c16b3c61cb..c12c786b4e 100644
--- a/module/repo/control.php
+++ b/module/repo/control.php
@@ -209,6 +209,9 @@ class repo extends control
             die(js::confirm($this->lang->repo->notice->delete, $this->repo->createLink('delete', "repoID=$repoID&objectID=$objectID&confirm=yes")));
         }
 
+        /* Delete project relation for gitlab type. */
+        $this->loadModel('gitlab')->deleteProjectRelation($repoID);
+
         $relationID = $this->dao->select('id')->from(TABLE_RELATION)->where('extra')->eq($repoID)->fetch();
         if($relationID)
         {