diff --git a/seahub/institutions/api_urls.py b/seahub/institutions/api_urls.py
new file mode 100644
index 00000000000..7b63bf56e8f
--- /dev/null
+++ b/seahub/institutions/api_urls.py
@@ -0,0 +1,13 @@
+# Copyright (c) 2012-2016 Seafile Ltd.
+from django.urls import path
+
+from .api_views import InstAdminUsers, InstAdminUser, \
+        InstAdminSearchUser, InstAdminLibraries, InstAdminGroups
+
+urlpatterns = [
+    path('admin/users/', InstAdminUsers.as_view(), name='api-v2.1-inst-admin-users'),
+    path('admin/users/<str:email>/', InstAdminUser.as_view(), name='api-v2.1-inst-admin-user'),
+    path('admin/search-user/', InstAdminSearchUser.as_view(), name='api-v2.1-inst-admin-search-user'),
+    path('admin/libraries/', InstAdminLibraries.as_view(), name='api-v2.1-inst-admin-libraries'),
+    path('admin/groups/', InstAdminGroups.as_view(), name='api-v2.1-inst-admin-groups'),
+]
diff --git a/seahub/institutions/api_views.py b/seahub/institutions/api_views.py
new file mode 100644
index 00000000000..32674660a4d
--- /dev/null
+++ b/seahub/institutions/api_views.py
@@ -0,0 +1,410 @@
+# Copyright (c) 2012-2016 Seafile Ltd.
+import logging
+
+from rest_framework import status
+from rest_framework.views import APIView
+from rest_framework.response import Response
+from rest_framework.permissions import BasePermission
+from rest_framework.authentication import SessionAuthentication
+
+from django.conf import settings
+from django.utils.translation import gettext as _
+
+from seaserv import ccnet_api, seafile_api
+
+from seahub.api2.utils import api_error
+from seahub.api2.permissions import IsProVersion
+from seahub.api2.throttling import UserRateThrottle
+from seahub.api2.authentication import TokenAuthentication
+
+from seahub.base.accounts import User
+from seahub.base.models import UserLastLogin
+from seahub.base.templatetags.seahub_tags import email2nickname, email2contact_email
+from seahub.profile.models import Profile
+from seahub.institutions.models import InstitutionAdmin
+from seahub.institutions.utils import get_institution_available_quota
+from seahub.utils.timeutils import datetime_to_isoformat_timestr
+from seahub.utils.timeutils import timestamp_to_isoformat_timestr
+from seahub.utils.file_size import get_file_size_unit
+from seahub.avatar.templatetags.avatar_tags import api_avatar_url
+
+
+logger = logging.getLogger(__name__)
+
+
+class IsInstAdmin(BasePermission):
+    """
+    Check whether is inst admin
+    """
+
+    def has_permission(self, request, *args, **kwargs):
+
+        # permission check
+        if not getattr(settings, 'MULTI_INSTITUTION', False):
+            return False
+
+        username = request.user.username
+
+        try:
+            inst_admin = InstitutionAdmin.objects.get(user=username)
+        except InstitutionAdmin.DoesNotExist:
+            inst_admin = False
+
+        if not inst_admin:
+            return False
+
+        inst = inst_admin.institution
+        profile = Profile.objects.get_profile_by_user(username)
+        if profile and profile.institution != inst.name:
+            return False
+
+        return True
+
+
+class InstAdminUsers(APIView):
+
+    authentication_classes = (TokenAuthentication, SessionAuthentication)
+    throttle_classes = (UserRateThrottle,)
+    permission_classes = (IsProVersion, IsInstAdmin)
+
+    def get(self, request):
+
+        """List users in institution.
+        """
+
+        username = request.user.username
+        inst_admin = InstitutionAdmin.objects.get(user=username)
+        inst = inst_admin.institution
+
+        # get user list
+        try:
+            current_page = int(request.GET.get('page', '1'))
+            per_page = int(request.GET.get('per_page', '100'))
+        except ValueError:
+            current_page = 1
+            per_page = 100
+
+        offset = per_page * (current_page - 1)
+        inst_users = Profile.objects.filter(institution=inst.name)[offset:offset + per_page]
+
+        admin_users = InstitutionAdmin.objects.filter(institution=inst)
+        admin_emails = [user.user for user in admin_users]
+
+        last_logins = UserLastLogin.objects.filter(username__in=[x.user for x in inst_users])
+
+        result = []
+        for user in inst_users:
+
+            email = user.user
+
+            user_info = {}
+            user_info['email'] = email
+            user_info['name'] = email2nickname(email)
+            user_info['contact_email'] = email2contact_email(email)
+            user_info['is_admin'] = email in admin_emails
+            user_info['avatar_url'], _, _ = api_avatar_url(email, 72)
+
+            try:
+                user_obj = User.objects.get(email=email)
+                user_info['is_active'] = user_obj.is_active
+            except User.DoesNotExist:
+                user_info['is_active'] = ''
+
+            user_info['last_login'] = ''
+            for last_login in last_logins:
+                if last_login.username == email:
+                    last_login_time = last_login.last_login
+                    user_info['last_login'] = datetime_to_isoformat_timestr(last_login_time)
+
+            try:
+                user_info['quota_total'] = seafile_api.get_user_quota(email)
+                user_info['quota_usage'] = seafile_api.get_user_self_usage(email)
+            except Exception as e:
+                logger.error(e)
+                user_info['quota_total'] = -1
+                user_info['quota_usage'] = -1
+
+            result.append(user_info)
+
+        return Response({
+            'user_list': result,
+            'total_count': inst_users.count()
+        })
+
+
+class InstAdminUser(APIView):
+
+    authentication_classes = (TokenAuthentication, SessionAuthentication)
+    throttle_classes = (UserRateThrottle,)
+    permission_classes = (IsProVersion, IsInstAdmin)
+
+    def put(self, request, email):
+
+        """ Set user info in institution.
+        """
+
+        username = request.user.username
+        inst_admin = InstitutionAdmin.objects.get(user=username)
+        inst = inst_admin.institution
+
+        try:
+            User.objects.get(email=email)
+        except User.DoesNotExist:
+            error_msg = f'User {email} not found.'
+            return api_error(status.HTTP_404_NOT_FOUND, error_msg)
+
+        profile = Profile.objects.get_profile_by_user(email)
+        if not profile or \
+                profile.institution != inst.name:
+            error_msg = f'User {email} not found in {inst.name}.'
+            return api_error(status.HTTP_404_NOT_FOUND, error_msg)
+
+        # set user quota
+        quota_total_mb = request.data.get("quota_total", None)
+        if not quota_total_mb:
+            error_msg = 'quota_total invalid.'
+            return api_error(status.HTTP_400_BAD_REQUEST, error_msg)
+
+        try:
+            quota_total_mb = int(quota_total_mb)
+        except ValueError:
+            error_msg = _("Must be an integer that is greater than or equal to 0.")
+            return api_error(status.HTTP_400_BAD_REQUEST, error_msg)
+
+        if quota_total_mb < 0:
+            error_msg = _("Space quota is too low (minimum value is 0).")
+            return api_error(status.HTTP_400_BAD_REQUEST, error_msg)
+
+        quota = quota_total_mb * get_file_size_unit('MB')
+        available_quota = get_institution_available_quota(inst)
+        if available_quota is not None:
+            # None means has unlimit quota
+            if available_quota == 0 or available_quota < quota:
+                error_msg = _(f"Failed to set quota: maximum quota is {available_quota} MB")
+                return api_error(status.HTTP_400_BAD_REQUEST, error_msg)
+
+        seafile_api.set_user_quota(email, quota)
+
+        return Response({'success': True})
+
+    def get(self, request, email):
+
+        """ Get user info in institution.
+        """
+
+        username = request.user.username
+        inst_admin = InstitutionAdmin.objects.get(user=username)
+        inst = inst_admin.institution
+
+        # get user info
+        try:
+            User.objects.get(email=email)
+        except User.DoesNotExist:
+            error_msg = f'User {email} not found.'
+            return api_error(status.HTTP_404_NOT_FOUND, error_msg)
+
+        profile = Profile.objects.get_profile_by_user(email)
+        if not profile or \
+                profile.institution != inst.name:
+            error_msg = f'User {email} not found in {inst.name}.'
+            return api_error(status.HTTP_404_NOT_FOUND, error_msg)
+
+        user_info = {}
+        user_info['email'] = email
+        user_info['name'] = email2nickname(email)
+        user_info['contact_email'] = email2contact_email(email)
+        user_info['avatar_url'], _, _ = api_avatar_url(email, 72)
+        try:
+            user_info['quota_total'] = seafile_api.get_user_quota(email)
+            user_info['quota_usage'] = seafile_api.get_user_self_usage(email)
+        except Exception as e:
+            logger.error(e)
+            user_info['quota_total'] = -1
+            user_info['quota_usage'] = -1
+
+        return Response(user_info)
+
+    def delete(self, request, email):
+
+        """ Delete user in institution.
+        """
+
+        # delete user
+        try:
+            user = User.objects.get(email=email)
+        except User.DoesNotExist:
+            error_msg = f'User {email} not found.'
+            return api_error(status.HTTP_404_NOT_FOUND, error_msg)
+
+        if user.is_staff:
+            error_msg = f'User {email} is system administrator.'
+            return api_error(status.HTTP_400_BAD_REQUEST, error_msg)
+
+        user.delete()
+        return Response({'success': True})
+
+
+class InstAdminSearchUser(APIView):
+
+    authentication_classes = (TokenAuthentication, SessionAuthentication)
+    throttle_classes = (UserRateThrottle,)
+    permission_classes = (IsProVersion, IsInstAdmin)
+
+    def get(self, request):
+
+        """Search user in institution.
+        """
+
+        username = request.user.username
+        inst_admin = InstitutionAdmin.objects.get(user=username)
+        inst = inst_admin.institution
+
+        # search user
+        q = request.GET.get('q', '').lower()
+        if not q:
+            error_msg = 'q invalid.'
+            return api_error(status.HTTP_400_BAD_REQUEST, error_msg)
+
+        inst_users = Profile.objects.filter(institution=inst.name)
+        admin_users = InstitutionAdmin.objects.filter(institution=inst)
+        admin_emails = [user.user for user in admin_users]
+        last_logins = UserLastLogin.objects.filter(username__in=[x.user for x in inst_users])
+
+        result = []
+        for user in inst_users:
+
+            email = user.user
+
+            if q not in email and \
+                    q not in email2nickname(email) and \
+                    q not in email2contact_email(email):
+                continue
+
+            user_info = {}
+            user_info['email'] = email
+            user_info['name'] = email2nickname(email)
+            user_info['contact_email'] = email2contact_email(email)
+            user_info['is_admin'] = email in admin_emails
+            user_info['avatar_url'], _, _ = api_avatar_url(email, 72)
+
+            try:
+                user_obj = User.objects.get(email=email)
+                user_info['is_active'] = user_obj.is_active
+            except User.DoesNotExist:
+                user_info['is_active'] = ''
+
+            user_info['last_login'] = ''
+            for last_login in last_logins:
+                if last_login.username == email:
+                    last_login_time = last_login.last_login
+                    user_info['last_login'] = datetime_to_isoformat_timestr(last_login_time)
+
+            try:
+                user_info['quota_total'] = seafile_api.get_user_quota(email)
+                user_info['quota_usage'] = seafile_api.get_user_self_usage(email)
+            except Exception as e:
+                logger.error(e)
+                user_info['quota_total'] = -1
+                user_info['quota_usage'] = -1
+
+            result.append(user_info)
+
+        return Response({'user_list': result})
+
+
+class InstAdminLibraries(APIView):
+
+    authentication_classes = (TokenAuthentication, SessionAuthentication)
+    throttle_classes = (UserRateThrottle,)
+    permission_classes = (IsProVersion, IsInstAdmin)
+
+    def get(self, request):
+
+        """Get user repos.
+        """
+
+        owner = request.GET.get('owner', '')
+        if not owner:
+            error_msg = 'owner invalid.'
+            return api_error(status.HTTP_400_BAD_REQUEST, error_msg)
+
+        try:
+            User.objects.get(email=owner)
+        except User.DoesNotExist:
+            error_msg = f'User {owner} not found.'
+            return api_error(status.HTTP_404_NOT_FOUND, error_msg)
+
+        username = request.user.username
+        inst_admin = InstitutionAdmin.objects.get(user=username)
+        inst = inst_admin.institution
+        profile = Profile.objects.get_profile_by_user(owner)
+        if not profile or \
+                profile.institution != inst.name:
+            error_msg = f'User {owner} not found in {inst.name}.'
+            return api_error(status.HTTP_404_NOT_FOUND, error_msg)
+
+        repo_info_list = []
+        owned_repos = seafile_api.get_owned_repo_list(owner)
+
+        for repo in owned_repos:
+
+            if repo.is_virtual:
+                continue
+
+            repo_info = {}
+            repo_info['id'] = repo.repo_id
+            repo_info['name'] = repo.repo_name
+            repo_info['size'] = repo.size
+            repo_info['last_modified'] = timestamp_to_isoformat_timestr(repo.last_modified)
+
+            repo_info_list.append(repo_info)
+
+        return Response({"repo_list": repo_info_list})
+
+
+class InstAdminGroups(APIView):
+
+    authentication_classes = (TokenAuthentication, SessionAuthentication)
+    throttle_classes = (UserRateThrottle,)
+    permission_classes = (IsProVersion, IsInstAdmin)
+
+    def get(self, request):
+
+        """Get user repos.
+        """
+
+        owner = request.GET.get('owner', '')
+        if not owner:
+            error_msg = 'owner invalid.'
+            return api_error(status.HTTP_400_BAD_REQUEST, error_msg)
+
+        try:
+            User.objects.get(email=owner)
+        except User.DoesNotExist:
+            error_msg = f'User {owner} not found.'
+            return api_error(status.HTTP_404_NOT_FOUND, error_msg)
+
+        username = request.user.username
+        inst_admin = InstitutionAdmin.objects.get(user=username)
+        inst = inst_admin.institution
+        profile = Profile.objects.get_profile_by_user(owner)
+        if not profile or \
+                profile.institution != inst.name:
+            error_msg = f'User {owner} not found in {inst.name}.'
+            return api_error(status.HTTP_404_NOT_FOUND, error_msg)
+
+        group_info_list = []
+        groups = ccnet_api.get_groups(owner)
+
+        for group in groups:
+
+            group_info = {}
+            group_info['id'] = group.id
+            group_info['name'] = group.group_name
+            group_info['is_owner'] = group.creator_name == owner
+            group_info['is_admin'] = ccnet_api.check_group_staff(group.id, owner)
+            group_info['created_at'] = timestamp_to_isoformat_timestr(group.timestamp)
+
+            group_info_list.append(group_info)
+
+        return Response({"groups_list": group_info_list})
diff --git a/seahub/urls.py b/seahub/urls.py
index 3d5bf276ecf..012cd0284d4 100644
--- a/seahub/urls.py
+++ b/seahub/urls.py
@@ -889,6 +889,11 @@
         path('org/', include('seahub.organizations.urls')),
     ]
 
+if getattr(settings, 'MULTI_INSTITUTION', False):
+    urlpatterns += [
+        re_path(r'^api/v2.1/institutions/', include('seahub.institutions.api_urls')),
+    ]
+
 if getattr(settings, 'ENABLE_SHIB_LOGIN', False):
     urlpatterns += [
         re_path(r'^shib-complete/', TemplateView.as_view(template_name='shibboleth/complete.html'), name="shib_complete"),