diff --git a/frontend/src/components/dialog/generate-share-link.js b/frontend/src/components/dialog/generate-share-link.js
index 6713f3ecaf..c6929b5378 100644
--- a/frontend/src/components/dialog/generate-share-link.js
+++ b/frontend/src/components/dialog/generate-share-link.js
@@ -128,6 +128,8 @@ class GenerateShareLink extends React.Component {
       seafileAPI.createShareLink(repoID, itemPath, password, expireDays, permissions).then((res) => {
         let sharedLinkInfo = new SharedLinkInfo(res.data);
         this.setState({sharedLinkInfo: sharedLinkInfo});
+      }).catch((error) => {
+        toaster.danger(error.response.data.error_msg);
       });
     }
   }
diff --git a/seahub/api2/endpoints/share_links.py b/seahub/api2/endpoints/share_links.py
index 8d4bef7cb8..32a34f5931 100644
--- a/seahub/api2/endpoints/share_links.py
+++ b/seahub/api2/endpoints/share_links.py
@@ -296,17 +296,21 @@ class ShareLinks(APIView):
         org_id = request.user.org.org_id if is_org_context(request) else None
         if s_type == 'f':
             fs = FileShare.objects.get_file_link_by_path(username, repo_id, path)
-            if not fs:
-                fs = FileShare.objects.create_file_link(username, repo_id, path,
-                                                        password, expire_date,
-                                                        permission=perm, org_id=org_id)
+            if fs:
+                error_msg = _(u'Share link %s already exists.' % fs.token)
+                return api_error(status.HTTP_400_BAD_REQUEST, error_msg)
+            fs = FileShare.objects.create_file_link(username, repo_id, path,
+                                                    password, expire_date,
+                                                    permission=perm, org_id=org_id)
 
         elif s_type == 'd':
             fs = FileShare.objects.get_dir_link_by_path(username, repo_id, path)
-            if not fs:
-                fs = FileShare.objects.create_dir_link(username, repo_id, path,
-                                                       password, expire_date,
-                                                       permission=perm, org_id=org_id)
+            if fs:
+                error_msg = _(u'Share link %s already exists.' % fs.token)
+                return api_error(status.HTTP_400_BAD_REQUEST, error_msg)
+            fs = FileShare.objects.create_dir_link(username, repo_id, path,
+                                                    password, expire_date,
+                                                    permission=perm, org_id=org_id)
 
         link_info = get_share_link_info(fs)
         return Response(link_info)
diff --git a/tests/api/endpoints/test_share_links.py b/tests/api/endpoints/test_share_links.py
index 2ce3259c11..d7fe686a0c 100644
--- a/tests/api/endpoints/test_share_links.py
+++ b/tests/api/endpoints/test_share_links.py
@@ -105,6 +105,23 @@ class ShareLinksTest(BaseTestCase):
 
         self._remove_share_link(json_resp['token'])
 
+    def test_create_duplicate_file_share_link(self):
+        self.login_as(self.user)
+
+        resp = self.client.post(self.url, {'path': self.file_path, 'repo_id': self.repo_id})
+        self.assertEqual(200, resp.status_code)
+        json_resp = json.loads(resp.content)
+        assert json_resp['token'] is not None
+        token = json_resp['token']
+
+        resp = self.client.post(self.url, {'path': self.file_path, 'repo_id': self.repo_id})
+        self.assertEqual(400, resp.status_code)
+        json_resp = json.loads(resp.content)
+        assert json_resp['error_msg'] is not None
+        assert token in json_resp['error_msg']
+
+        self._remove_share_link(token)
+
     def test_create_file_share_link_in_enc_repo(self):
         self.login_as(self.user)
 
@@ -208,6 +225,23 @@ class ShareLinksTest(BaseTestCase):
 
         self._remove_share_link(json_resp['token'])
 
+    def test_create_duplicate_dir_share_link(self):
+        self.login_as(self.user)
+
+        resp = self.client.post(self.url, {'path': self.folder_path, 'repo_id': self.repo_id})
+        self.assertEqual(200, resp.status_code)
+        json_resp = json.loads(resp.content)
+        assert json_resp['token'] is not None
+        token = json_resp['token']
+
+        resp = self.client.post(self.url, {'path': self.folder_path, 'repo_id': self.repo_id})
+        self.assertEqual(400, resp.status_code)
+        json_resp = json.loads(resp.content)
+        assert json_resp['error_msg'] is not None
+        assert token in json_resp['error_msg']
+
+        self._remove_share_link(token)
+
     def test_create_link_with_invalid_repo_permission(self):
         # login with admin to create share link in user repo
         self.login_as(self.admin)