diff --git a/frontend/src/components/dialog/import-members-dialog.js b/frontend/src/components/dialog/import-members-dialog.js
new file mode 100644
index 0000000000..9700611ef4
--- /dev/null
+++ b/frontend/src/components/dialog/import-members-dialog.js
@@ -0,0 +1,68 @@
+import React from 'react';
+import PropTypes from 'prop-types';
+import { Alert, Modal, ModalHeader, ModalBody, ModalFooter, Button } from 'reactstrap';
+import { gettext, siteRoot } from '../../utils/constants';
+
+const propTypes = {
+  toggleImportMembersDialog: PropTypes.func.isRequired,
+  importMembersInBatch: PropTypes.func.isRequired,
+};
+
+class ImportMembersDialog extends React.Component {
+  constructor(props) {
+    super(props);
+    this.fileInputRef = React.createRef();
+    this.state = {
+      errorMsg: ''
+    };
+  }
+
+  toggle = () => {
+    this.props.toggleImportMembersDialog();
+  }
+
+  openFileInput = () => {
+    this.fileInputRef.current.click();
+  }
+
+  uploadFile = (e) => {
+    // no file selected
+    if (!this.fileInputRef.current.files.length) {
+      return;
+    }
+    // check file extension
+    let fileName = this.fileInputRef.current.files[0].name;
+    if(fileName.substr(fileName.lastIndexOf('.') + 1) != 'xlsx') {
+      this.setState({
+        errorMsg: gettext('Please choose a .xlsx file.')
+      });
+      return;
+    }
+    const file = this.fileInputRef.current.files[0];
+    this.props.importMembersInBatch(file);
+    this.toggle();
+  }
+
+  render() {
+    let { errorMsg } = this.state;
+    return (
+      <Modal isOpen={true} toggle={this.toggle}>
+        <ModalHeader toggle={this.toggle}>{gettext('Import members from a .xlsx file')}</ModalHeader>
+
+        <ModalBody>
+          <p><a className="text-secondary small" href={`${siteRoot}api/v2.1/group-members-import-example/`}>{gettext('Download an example file')}</a></p>
+          <button className="btn btn-outline-primary" onClick={this.openFileInput}>{gettext('Upload file')}</button>
+          <input className="d-none" type="file" onChange={this.uploadFile} ref={this.fileInputRef} />
+          {errorMsg && <Alert color="danger">{errorMsg}</Alert>}
+        </ModalBody>
+        <ModalFooter>
+          <Button color="secondary" onClick={this.toggle}>{gettext('Cancel')}</Button>
+        </ModalFooter>
+      </Modal>
+    );
+  }
+}
+
+ImportMembersDialog.propTypes = propTypes;
+
+export default ImportMembersDialog;
diff --git a/frontend/src/pages/groups/group-view.js b/frontend/src/pages/groups/group-view.js
index c16c351c8d..d0bd60e1e8 100644
--- a/frontend/src/pages/groups/group-view.js
+++ b/frontend/src/pages/groups/group-view.js
@@ -18,7 +18,7 @@ import CreateDepartmentRepoDialog from '../../components/dialog/create-departmen
 import DismissGroupDialog from '../../components/dialog/dismiss-group-dialog';
 import RenameGroupDialog from '../../components/dialog/rename-group-dialog';
 import TransferGroupDialog from '../../components/dialog/transfer-group-dialog';
-// import ImportMembersDialog from '../../components/dialog/import-members-dialog';
+import ImportMembersDialog from '../../components/dialog/import-members-dialog';
 import ManageMembersDialog from '../../components/dialog/manage-members-dialog';
 import LeaveGroupDialog from '../../components/dialog/leave-group-dialog';
 import SharedRepoListView from '../../components/shared-repo-list-view/shared-repo-list-view';
@@ -63,7 +63,7 @@ class GroupView extends React.Component {
       showRenameGroupDialog: false,
       showDismissGroupDialog: false,
       showTransferGroupDialog: false,
-      // showImportMembersDialog: false,
+      showImportMembersDialog: false,
       showManageMembersDialog: false,
       groupMembers: [],
       isShowDetails: false,
@@ -283,11 +283,24 @@ class GroupView extends React.Component {
     });
   }
 
-  // toggleImportMembersDialog= () => {
-  //   this.setState({
-  //     showImportMembersDialog: !this.state.showImportMembersDialog
-  //   });
-  // }
+  toggleImportMembersDialog= () => {
+    this.setState({
+      showImportMembersDialog: !this.state.showImportMembersDialog
+    });
+  }
+
+  importMembersInBatch= (file) => {
+    toaster.notify(gettext('It may take some time, please wait.'));
+    seafileAPI.importGroupMembersViaFile(this.state.currentGroup.id, file).then((res) => {
+      res.data.failed.map(item => {
+        const msg = `${item.email}: ${item.error_msg}`;
+        toaster.danger(msg);
+      });
+    }).catch((error) => {
+      let errMsg = Utils.getErrorMsg(error);
+      toaster.danger(errMsg);
+    });
+  }
 
   toggleManageMembersDialog = () => {
     this.setState({
@@ -464,7 +477,7 @@ class GroupView extends React.Component {
                           }
                           {(this.state.isStaff || this.state.isOwner) &&
                           <ul className="sf-popover-list">
-                            {/* <li><a href="#" className="sf-popover-item" onClick={this.toggleImportMembersDialog} >{gettext('Import Members')}</a></li> */}
+                            <li><a href="#" className="sf-popover-item" onClick={this.toggleImportMembersDialog} >{gettext('Import Members')}</a></li>
                             <li><a href="#" className="sf-popover-item" onClick={this.toggleManageMembersDialog} >{gettext('Manage Members')}</a></li>
                           </ul>
                           }
@@ -596,13 +609,12 @@ class GroupView extends React.Component {
             onGroupChanged={this.props.onGroupChanged}
           />
         }
-        {/* this.state.showImportMembersDialog &&
+        { this.state.showImportMembersDialog &&
           <ImportMembersDialog
             toggleImportMembersDialog={this.toggleImportMembersDialog}
-            groupID={this.props.groupID}
-            onGroupChanged={this.props.onGroupChanged}
+            importMembersInBatch={this.importMembersInBatch}
           />
-        */}
+        }
         {this.state.showManageMembersDialog &&
           <ManageMembersDialog
             toggleManageMembersDialog={this.toggleManageMembersDialog}
diff --git a/seahub/api2/endpoints/group_members.py b/seahub/api2/endpoints/group_members.py
index 8f364001c5..725a1fe4d5 100644
--- a/seahub/api2/endpoints/group_members.py
+++ b/seahub/api2/endpoints/group_members.py
@@ -1,6 +1,9 @@
 # Copyright (c) 2012-2016 Seafile Ltd.
 import logging
+from io import BytesIO
+from openpyxl import load_workbook
 
+from django.http import HttpResponse
 from django.utils.translation import ugettext as _
 
 from rest_framework.authentication import SessionAuthentication
@@ -9,16 +12,18 @@ from rest_framework.response import Response
 from rest_framework.views import APIView
 from rest_framework import status
 
-import seaserv
 from seaserv import seafile_api, ccnet_api
 from pysearpc import SearpcError
 
 from seahub.api2.utils import api_error
+from seahub.api2.endpoints.utils import is_org_user
 from seahub.api2.throttling import UserRateThrottle
 from seahub.api2.authentication import TokenAuthentication
 from seahub.avatar.settings import AVATAR_DEFAULT_SIZE
 from seahub.base.templatetags.seahub_tags import email2nickname
-from seahub.utils import string2list, is_org_context
+from seahub.utils import string2list, is_org_context, get_file_type_and_ext
+from seahub.utils.ms_excel import write_xls
+from seahub.utils.error_msg import file_type_error_msg
 from seahub.base.accounts import User
 from seahub.group.signals import add_user_to_group
 from seahub.group.utils import is_group_member, is_group_admin, \
@@ -28,6 +33,7 @@ from .utils import api_check_group
 
 logger = logging.getLogger(__name__)
 
+
 class GroupMembers(APIView):
     authentication_classes = (TokenAuthentication, SessionAuthentication)
     permission_classes = (IsAuthenticated,)
@@ -40,8 +46,7 @@ class GroupMembers(APIView):
         """
 
         try:
-            avatar_size = int(request.GET.get('avatar_size',
-                AVATAR_DEFAULT_SIZE))
+            avatar_size = int(request.GET.get('avatar_size', AVATAR_DEFAULT_SIZE))
         except ValueError:
             avatar_size = AVATAR_DEFAULT_SIZE
 
@@ -109,6 +114,9 @@ class GroupMembers(APIView):
                 if not ccnet_api.org_user_exists(org_id, email):
                     error_msg = _('User %s not found in organization.') % email2nickname(email)
                     return api_error(status.HTTP_404_NOT_FOUND, error_msg)
+            elif is_org_user(email):
+                error_msg = _('User %s is an organization user.') % email
+                return api_error(status.HTTP_404_NOT_FOUND, error_msg)
 
             ccnet_api.group_add_member(group_id, username, email)
             add_user_to_group.send(sender=None,
@@ -151,8 +159,7 @@ class GroupMember(APIView):
             return api_error(status.HTTP_500_INTERNAL_SERVER_ERROR, error_msg)
 
         try:
-            avatar_size = int(request.GET.get('avatar_size',
-                AVATAR_DEFAULT_SIZE))
+            avatar_size = int(request.GET.get('avatar_size', AVATAR_DEFAULT_SIZE))
         except ValueError:
             avatar_size = AVATAR_DEFAULT_SIZE
 
@@ -305,8 +312,7 @@ class GroupMembersBulk(APIView):
                 continue
 
             # Can only invite organization users to group
-            if org_id and not \
-                seaserv.ccnet_threaded_rpc.org_user_exists(org_id, email):
+            if org_id and not ccnet_api.org_user_exists(org_id, email):
                 result['failed'].append({
                     'email': email,
                     'email_name': email_name,
@@ -314,13 +320,20 @@ class GroupMembersBulk(APIView):
                     })
                 continue
 
+            if not org_id and is_org_user(email):
+                result['failed'].append({
+                    'email': email,
+                    'email_name': email_name,
+                    'error_msg': _('User %s is an organization user.') % email_name
+                    })
+                continue
+
             emails_need_add.append(email)
 
         # Add user to group.
         for email in emails_need_add:
             try:
-                seaserv.ccnet_threaded_rpc.group_add_member(group_id,
-                    username, email)
+                ccnet_api.group_add_member(group_id, username, email)
                 member_info = get_group_member_info(request, group_id, email)
                 result['success'].append(member_info)
             except SearpcError as e:
@@ -335,3 +348,158 @@ class GroupMembersBulk(APIView):
                                    group_id=group_id,
                                    added_user=email)
         return Response(result)
+
+
+class GroupMembersImport(APIView):
+
+    authentication_classes = (TokenAuthentication, SessionAuthentication)
+    permission_classes = (IsAuthenticated,)
+    throttle_classes = (UserRateThrottle,)
+
+    def post(self, request, group_id):
+
+        """ Import members from xlsx file
+
+        Permission checking:
+        1. group admin or owner.
+        """
+
+        xlsx_file = request.FILES.get('file', None)
+        if not xlsx_file:
+            error_msg = 'file can not be found.'
+            return api_error(status.HTTP_400_BAD_REQUEST, error_msg)
+
+        file_type, ext = get_file_type_and_ext(xlsx_file.name)
+        if ext != 'xlsx':
+            error_msg = file_type_error_msg(ext, 'xlsx')
+            return api_error(status.HTTP_400_BAD_REQUEST, error_msg)
+
+        # recourse check
+        group_id = int(group_id)
+        group = ccnet_api.get_group(group_id)
+        if not group:
+            error_msg = _('Group does not exist')
+            return api_error(status.HTTP_404_NOT_FOUND, error_msg)
+
+        # check permission
+        # only group owner/admin can add group members
+        username = request.user.username
+        if not is_group_admin_or_owner(group_id, username):
+            error_msg = 'Permission denied.'
+            return api_error(status.HTTP_403_FORBIDDEN, error_msg)
+
+        content = xlsx_file.read()
+
+        try:
+            fs = BytesIO(content)
+            wb = load_workbook(filename=fs, read_only=True)
+        except Exception as e:
+            logger.error(e)
+
+        # example file is like:
+        # Email
+        # a@a.com
+        # b@b.com
+
+        rows = wb.worksheets[0].rows
+        records = []
+        # skip first row(head field).
+        next(rows)
+        for row in rows:
+            records.append([col.value for col in row])
+
+        emails_list = []
+        for record in records:
+            if record[0]:
+                email = record[0].strip().lower()
+                emails_list.append(email)
+
+        result = {}
+        result['failed'] = []
+        result['success'] = []
+        emails_need_add = []
+
+        org_id = None
+        if is_org_context(request):
+            org_id = request.user.org.org_id
+
+        for email in emails_list:
+            email_name = email2nickname(email)
+            try:
+                User.objects.get(email=email)
+            except User.DoesNotExist:
+                result['failed'].append({
+                    'email': email,
+                    'email_name': email_name,
+                    'error_msg': 'User %s not found.' % email_name
+                    })
+                continue
+
+            if is_group_member(group_id, email, in_structure=False):
+                result['failed'].append({
+                    'email': email,
+                    'email_name': email_name,
+                    'error_msg': _('User %s is already a group member.') % email_name
+                    })
+                continue
+
+            # Can only invite organization users to group
+            if org_id and not ccnet_api.org_user_exists(org_id, email):
+                result['failed'].append({
+                    'email': email,
+                    'email_name': email_name,
+                    'error_msg': _('User %s not found in organization.') % email_name
+                    })
+                continue
+
+            if not org_id and is_org_user(email):
+                result['failed'].append({
+                    'email': email,
+                    'email_name': email_name,
+                    'error_msg': _('User %s is an organization user.') % email_name
+                    })
+                continue
+
+            emails_need_add.append(email)
+
+        # Add user to group.
+        for email in emails_need_add:
+            try:
+                ccnet_api.group_add_member(group_id, username, email)
+                member_info = get_group_member_info(request, group_id, email)
+                result['success'].append(member_info)
+            except SearpcError as e:
+                logger.error(e)
+                result['failed'].append({
+                    'email': email,
+                    'error_msg': 'Internal Server Error'
+                    })
+
+            add_user_to_group.send(sender=None,
+                                   group_staff=username,
+                                   group_id=group_id,
+                                   added_user=email)
+        return Response(result)
+
+
+class GroupMembersImportExample(APIView):
+
+    throttle_classes = (UserRateThrottle, )
+
+    def get(self, request):
+
+        data_list = []
+        head = [_('Email')]
+        for i in range(5):
+            username = "test" + str(i) + "@example.com"
+            data_list.append([username])
+
+        wb = write_xls('sample', head, data_list)
+        if not wb:
+            return api_error(status.HTTP_500_INTERNAL_SERVER_ERROR, _('Failed to export Excel'))
+
+        response = HttpResponse(content_type='application/ms-excel')
+        response['Content-Disposition'] = 'attachment; filename=members.xlsx'
+        wb.save(response)
+
+        return response
diff --git a/seahub/urls.py b/seahub/urls.py
index 3804e6418e..68478f283b 100644
--- a/seahub/urls.py
+++ b/seahub/urls.py
@@ -34,7 +34,8 @@ from seahub.api2.endpoints.group_owned_libraries import GroupOwnedLibraries, \
 from seahub.api2.endpoints.address_book.groups import AddressBookGroupsSubGroups
 from seahub.api2.endpoints.address_book.members import AddressBookGroupsSearchMember
 
-from seahub.api2.endpoints.group_members import GroupMembers, GroupMembersBulk, GroupMember
+from seahub.api2.endpoints.group_members import GroupMembers, GroupMember, \
+        GroupMembersBulk, GroupMembersImport, GroupMembersImportExample
 from seahub.api2.endpoints.search_group import SearchGroup
 from seahub.api2.endpoints.share_links import ShareLinks, ShareLink, \
         ShareLinkOnlineOfficeLock, ShareLinkDirents, ShareLinkSaveFileToRepo
@@ -290,6 +291,8 @@ urlpatterns = [
     url(r'^api/v2.1/groups/(?P<group_id>\d+)/group-owned-libraries/(?P<repo_id>[-0-9a-f]{36})/$', GroupOwnedLibrary.as_view(), name='api-v2.1-owned-group-library'),
     url(r'^api/v2.1/groups/(?P<group_id>\d+)/members/$', GroupMembers.as_view(), name='api-v2.1-group-members'),
     url(r'^api/v2.1/groups/(?P<group_id>\d+)/members/bulk/$', GroupMembersBulk.as_view(), name='api-v2.1-group-members-bulk'),
+    url(r'^api/v2.1/groups/(?P<group_id>\d+)/members/import/$', GroupMembersImport.as_view(), name='api-v2.1-group-members-import'),
+    url(r'^api/v2.1/group-members-import-example/$', GroupMembersImportExample.as_view(), name='api-v2.1-group-members-import-example'),
     url(r'^api/v2.1/groups/(?P<group_id>\d+)/members/(?P<email>[^/]+)/$', GroupMember.as_view(), name='api-v2.1-group-member'),
     url(r'^api/v2.1/search-group/$', SearchGroup.as_view(), name='api-v2.1-search-group'),