diff --git a/cyborg/api/controllers/v2/arqs.py b/cyborg/api/controllers/v2/arqs.py
index 38fbafb9..9630b4dd 100644
--- a/cyborg/api/controllers/v2/arqs.py
+++ b/cyborg/api/controllers/v2/arqs.py
@@ -23,6 +23,8 @@ from oslo_log import log
 from cyborg.api.controllers import base
 from cyborg.api.controllers import link
 from cyborg.api.controllers import types
+from cyborg.api.controllers.v2 import utils
+from cyborg.api.controllers.v2 import versions
 from cyborg.api import expose
 from cyborg.common import constants
 from cyborg.common import exception
@@ -54,6 +56,8 @@ class ARQ(base.APIBase):
 
     instance_uuid = wtypes.text
     """The UUID of the instance associated with this ARQ, if any"""
+    project_id = wtypes.text
+    """The UUID of the instance project_id associated with this ARQ, if any"""
 
     attach_handle_type = wtypes.text
     attach_handle_info = {wtypes.text: wtypes.text}
@@ -257,6 +261,8 @@ class ARQsController(base.CyborgController):
         valid_fields = {'hostname': None,
                         'device_rp_uuid': None,
                         'instance_uuid': None}
+        if utils.allow_project_id():
+            valid_fields['project_id'] = None
         if ((not all(p['op'] == 'add' for p in patch)) and
            (not all(p['op'] == 'remove' for p in patch))):
             raise exception.PatchError(
@@ -264,6 +270,12 @@ class ARQsController(base.CyborgController):
 
         for p in patch:
             path = p['path'].lstrip('/')
+            if path == 'project_id' and not utils.allow_project_id():
+                raise exception.NotAcceptable(_(
+                    "Request not acceptable. The minimal required API "
+                    "version should be %(base)s.%(opr)s") %
+                    {'base': versions.BASE_VERSION,
+                     'opr': versions.MINOR_1_PROJECT_ID})
             if path not in valid_fields.keys():
                 reason = 'Invalid path in patch {}'.format(p['path'])
                 raise exception.PatchError(reason=reason)
@@ -306,6 +318,7 @@ class ARQsController(base.CyborgController):
                 {"path": "/hostname", "op": ADD/RM, "value": "..."},
                 {"path": "/device_rp_uuid", "op": ADD/RM, "value": "..."},
                 {"path": "/instance_uuid", "op": ADD/RM, "value": "..."},
+                {"path": "/project_id", "op": ADD/RM, "value": "..."},
                ],
              "$arq_uuid": [...]
             }
diff --git a/cyborg/api/controllers/v2/utils.py b/cyborg/api/controllers/v2/utils.py
new file mode 100644
index 00000000..613c338d
--- /dev/null
+++ b/cyborg/api/controllers/v2/utils.py
@@ -0,0 +1,22 @@
+# Copyright 2020 Inspur, Inc.
+# All Rights Reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+from cyborg import api
+from cyborg.api.controllers.v2 import versions
+
+
+def allow_project_id():
+    # v2.1 added project_id for arq patch
+    return api.request.version.minor >= versions.MINOR_1_PROJECT_ID
diff --git a/cyborg/api/controllers/v2/versions.py b/cyborg/api/controllers/v2/versions.py
index ad52d314..2de475f0 100644
--- a/cyborg/api/controllers/v2/versions.py
+++ b/cyborg/api/controllers/v2/versions.py
@@ -23,7 +23,9 @@ BASE_VERSION = 2
 # explanation of what each version contains.
 #
 # v2.0: Initial minor version.
+# v2.1: Add project_id for arq patch
 MINOR_0_INITIAL_VERSION = 0
+MINOR_1_PROJECT_ID = 1
 
 
 # When adding another version, update:
@@ -32,7 +34,7 @@ MINOR_0_INITIAL_VERSION = 0
 #   explanation of what changed in the new version
 
 
-MINOR_MAX_VERSION = MINOR_0_INITIAL_VERSION
+MINOR_MAX_VERSION = MINOR_1_PROJECT_ID
 
 # String representations of the minor and maximum versions
 _MIN_VERSION_STRING = '{}.{}'.format(BASE_VERSION, MINOR_0_INITIAL_VERSION)
diff --git a/cyborg/api/rest_api_version_history.rst b/cyborg/api/rest_api_version_history.rst
index 970ef6eb..7b56abd0 100644
--- a/cyborg/api/rest_api_version_history.rst
+++ b/cyborg/api/rest_api_version_history.rst
@@ -12,6 +12,11 @@ user documentation.
 This is the initial version of the v2 API which supports
 microversions.
 
+2.1
+---
+
+Add ``project_id`` for arq.
+
 A user can specify a header in the API request::
 
   OpenStack-API-Version: accelerator <microversion>
diff --git a/cyborg/common/exception.py b/cyborg/common/exception.py
index e368db45..567115c7 100644
--- a/cyborg/common/exception.py
+++ b/cyborg/common/exception.py
@@ -411,3 +411,8 @@ class InvalidType(Invalid):
 
 class ResourceNotFound(NotFound):
     _msg_fmt = _("%(resource)s not found %(msg)s")
+
+
+class NotAcceptable(CyborgException):
+    _msg_fmt = _("Request not acceptable.")
+    code = http_client.NOT_ACCEPTABLE
diff --git a/cyborg/objects/arq.py b/cyborg/objects/arq.py
index e4d6dc6b..033039ad 100644
--- a/cyborg/objects/arq.py
+++ b/cyborg/objects/arq.py
@@ -44,6 +44,7 @@ class ARQ(base.CyborgObject, object_base.VersionedObjectDictCompat):
         'hostname': object_fields.StringField(nullable=True),
         'device_rp_uuid': object_fields.StringField(nullable=True),
         'instance_uuid': object_fields.StringField(nullable=True),
+        'project_id': object_fields.StringField(nullable=True),
 
         # Fields populated by Cyborg after binding
         'attach_handle_type': object_fields.StringField(nullable=True),
@@ -66,6 +67,6 @@ class ARQ(base.CyborgObject, object_base.VersionedObjectDictCompat):
             db_extarq['attach_handle_info'] = {}
 
         for field in arq.fields:
-            arq[field] = db_extarq[field]
+            arq[field] = db_extarq.get(field)
         arq.obj_reset_changes()
         return arq
diff --git a/cyborg/objects/ext_arq.py b/cyborg/objects/ext_arq.py
index 332b22ec..681962de 100644
--- a/cyborg/objects/ext_arq.py
+++ b/cyborg/objects/ext_arq.py
@@ -278,7 +278,7 @@ class ExtARQ(base.CyborgObject, object_base.VersionedObjectDictCompat,
 
         for field in extarq.fields:
             if field != 'arq':
-                extarq[field] = db_extarq[field]
+                extarq[field] = db_extarq.get(field)
         extarq.arq = objects.ARQ()
         extarq.arq._from_db_object(extarq.arq, db_extarq)
         extarq.obj_reset_changes()
diff --git a/cyborg/objects/extarq/ext_arq_job.py b/cyborg/objects/extarq/ext_arq_job.py
index cb211401..75736443 100644
--- a/cyborg/objects/extarq/ext_arq_job.py
+++ b/cyborg/objects/extarq/ext_arq_job.py
@@ -65,12 +65,17 @@ class ExtARQJobMixin(object):
         hostname = valid_fields[self.arq.uuid]['hostname']
         devrp_uuid = valid_fields[self.arq.uuid]['device_rp_uuid']
         instance_uuid = valid_fields[self.arq.uuid]['instance_uuid']
-        LOG.info('[arqs:objs] bind. hostname: %s, devrp_uuid: %s'
-                 'instance: %s', hostname, devrp_uuid, instance_uuid)
+        project_id = valid_fields[self.arq.uuid].get('project_id')
+        LOG.info('[arqs:objs] bind. hostname: %(hostname)s,'
+                 ' devrp_uuid: %(devrp_uuid)s, instance: %(instance)s, '
+                 'project_id: %(project_id)s',
+                 {'hostname': hostname, 'devrp_uuid': devrp_uuid,
+                  'instance_uuid': instance_uuid, 'project_id': project_id})
 
         self.arq.hostname = hostname
         self.arq.device_rp_uuid = devrp_uuid
         self.arq.instance_uuid = instance_uuid
+        self.arq.project_id = project_id
 
         # If prog fails, we'll change this ARQ state changes get committed here
         self.update_check_state(context, constants.ARQ_BIND_STARTED)
diff --git a/cyborg/tests/unit/api/controllers/v2/test_arqs.py b/cyborg/tests/unit/api/controllers/v2/test_arqs.py
index ba45371a..092fa2e5 100644
--- a/cyborg/tests/unit/api/controllers/v2/test_arqs.py
+++ b/cyborg/tests/unit/api/controllers/v2/test_arqs.py
@@ -19,6 +19,7 @@ from unittest import mock
 
 from oslo_serialization import jsonutils
 
+from cyborg.api.controllers import base
 from cyborg.api.controllers.v2 import arqs
 from cyborg.common import exception
 from cyborg.tests.unit.api.controllers.v2 import base as v2_test
@@ -255,13 +256,14 @@ class TestARQsController(v2_test.APITestV2):
     @mock.patch('cyborg.objects.ExtARQ.apply_patch')
     def test_apply_patch(self, mock_apply_patch, mock_check_if_bound):
         """Test the happy path."""
-        patch_list = fake_extarq.get_patch_list()
+        patch_list, device_rp_uuid = fake_extarq.get_patch_list()
         arq_uuids = list(patch_list.keys())
+        obj_extarq = self.fake_extarqs[0]
         valid_fields = {
             arq_uuid: {
-                'hostname': 'myhost',
-                'device_rp_uuid': 'fb16c293-5739-4c84-8590-926f9ab16669',
-                'instance_uuid': '5922a70f-1e06-4cfd-88dd-a332120d7144'}
+                'hostname': obj_extarq.arq.hostname,
+                'device_rp_uuid': device_rp_uuid,
+                'instance_uuid': obj_extarq.arq.instance_uuid}
             for arq_uuid in arq_uuids}
 
         self.patch_json(self.ARQ_URL, params=patch_list,
@@ -271,6 +273,41 @@ class TestARQsController(v2_test.APITestV2):
                                                  valid_fields)
         mock_check_if_bound.assert_called_once_with(mock.ANY, valid_fields)
 
+    @mock.patch.object(arqs.ARQsController, '_check_if_already_bound')
+    @mock.patch('cyborg.objects.ExtARQ.apply_patch')
+    def test_apply_patch_allow_project_id(
+            self, mock_apply_patch, mock_check_if_bound):
+        patch_list, _ = fake_extarq.get_patch_list()
+        for arq_uuid, patch in patch_list.items():
+            patch.append({'path': '/project_id', 'op': 'add',
+                          'value': 'b1c76756ac2e482789a8e1c5f4bf065e'})
+        arq_uuids = list(patch_list.keys())
+        valid_fields = {
+            arq_uuid: {
+                'hostname': 'myhost',
+                'device_rp_uuid': 'fb16c293-5739-4c84-8590-926f9ab16669',
+                'instance_uuid': '5922a70f-1e06-4cfd-88dd-a332120d7144',
+                'project_id': 'b1c76756ac2e482789a8e1c5f4bf065e'}
+            for arq_uuid in arq_uuids}
+
+        self.patch_json(self.ARQ_URL, params=patch_list,
+                        headers={base.Version.current_api_version:
+                                 'accelerator 2.1'})
+        mock_apply_patch.assert_called_once_with(mock.ANY, patch_list,
+                                                 valid_fields)
+        mock_check_if_bound.assert_called_once_with(mock.ANY, valid_fields)
+
+    def test_apply_patch_not_allow_project_id(self):
+        patch_list, _ = fake_extarq.get_patch_list()
+        for arq_uuid, patch in patch_list.items():
+            patch.append({'path': '/project_id', 'op': 'add',
+                          'value': 'b1c76756ac2e482789a8e1c5f4bf065e'})
+        response = self.patch_json(self.ARQ_URL, params=patch_list,
+                                   headers=self.headers,
+                                   expect_errors=True)
+        self.assertEqual(http_client.NOT_ACCEPTABLE, response.status_code)
+        self.assertTrue(response.json['error_message'])
+
     # TODO(all): Add exception test cases for apply_patch.
 
     @mock.patch('cyborg.objects.ExtARQ.list')
diff --git a/cyborg/tests/unit/fake_extarq.py b/cyborg/tests/unit/fake_extarq.py
index 6067a488..d51ca4c2 100644
--- a/cyborg/tests/unit/fake_extarq.py
+++ b/cyborg/tests/unit/fake_extarq.py
@@ -288,7 +288,8 @@ def get_patch_list(same_device=True):
         must be for the same device.
     """
     arqs = _get_arqs_as_dict()
-    host_binding = {'path': '/hostname', 'op': 'add', 'value': 'myhost'}
+    host_binding = {'path': '/hostname', 'op': 'add',
+                    'value': arqs[0]['hostname']}
     inst_binding = {'path': '/instance_uuid', 'op': 'add',
                     'value': arqs[0]['instance_uuid']}
     device_rp_uuid = 'fb16c293-5739-4c84-8590-926f9ab16669'
@@ -298,4 +299,4 @@ def get_patch_list(same_device=True):
         dev_binding = {'path': '/device_rp_uuid', 'op': 'add',
                        'value': dev_uuid}
         patch_list[newarq['uuid']] = [host_binding, inst_binding, dev_binding]
-    return patch_list
+    return patch_list, device_rp_uuid