diff --git a/HACKING.rst b/HACKING.rst
index 4a35d3d33..5dbcda3bc 100644
--- a/HACKING.rst
+++ b/HACKING.rst
@@ -9,6 +9,7 @@ Tacker Specific Commandments
 ----------------------------
 
 - [N320] Validate that LOG messages, except debug ones, have translations
+- [T301] Log.warn is deprecated. Enforce use of LOG.warning.
 
 Creating Unit Tests
 -------------------
diff --git a/samples/mgmt_driver/kubernetes_mgmt.py b/samples/mgmt_driver/kubernetes_mgmt.py
index de2a43fd4..2a22f3cd6 100644
--- a/samples/mgmt_driver/kubernetes_mgmt.py
+++ b/samples/mgmt_driver/kubernetes_mgmt.py
@@ -274,7 +274,7 @@ class KubernetesMgmtDriver(vnflcm_abstract_driver.VnflcmMgmtAbstractDriver):
             msg = 'Failed to find specified zone id' \
                   ' related to Vnfc Resource {} in grant'.format(
                       vnfc_id)
-            LOG.warn(msg)
+            LOG.warning(msg)
         else:
             for zone in grant.zones:
                 if add_resource_zone_id == zone.id:
diff --git a/tacker/conductor/conductor_server.py b/tacker/conductor/conductor_server.py
index 6b7f1054c..38f5bd532 100644
--- a/tacker/conductor/conductor_server.py
+++ b/tacker/conductor/conductor_server.py
@@ -1791,7 +1791,7 @@ class Conductor(manager.Manager, v2_hook.ConductorV2Hook):
                         notification_type=notification.get('notificationType')
                     )
             if not vnf_lcm_subscriptions:
-                LOG.warn(
+                LOG.warning(
                     "vnf_lcm_subscription not found id[%s]" %
                     notification.get('vnfInstanceId'))
                 return -1
@@ -1851,20 +1851,20 @@ class Conductor(manager.Manager, v2_hook.ConductorV2Hook):
                                     "reason": str(e)})
                             self._retry_check(num)
                 except Exception as e:
-                    LOG.warn("send error[%s]" % str(e))
-                    LOG.warn(traceback.format_exc())
+                    LOG.warning("send error[%s]" % str(e))
+                    LOG.warning(traceback.format_exc())
                     continue
 
         except Exception as e:
-            LOG.warn("Internal Sever Error[%s]" % str(e))
-            LOG.warn(traceback.format_exc())
+            LOG.warning("Internal Sever Error[%s]" % str(e))
+            LOG.warning(traceback.format_exc())
             return -2
         return 0
 
     def _retry_check(self, retry_count):
         time.sleep(CONF.vnf_lcm.retry_wait)
         if retry_count == CONF.vnf_lcm.retry_num:
-            LOG.warn(
+            LOG.warning(
                 "Number of retries exceeded retry count [%s]" %
                 CONF.vnf_lcm.retry_num)
 
diff --git a/tacker/glance_store/store.py b/tacker/glance_store/store.py
index 4b234fe51..b362d0eff 100644
--- a/tacker/glance_store/store.py
+++ b/tacker/glance_store/store.py
@@ -52,8 +52,8 @@ def get_csar_data_iter(body):
         return data_iter
     except Exception as e:
         error = encodeutils.exception_to_unicode(e)
-        LOG.warn("Failed to open csar URL: %(url)s due to error: %(error)s",
-                 {"url": url, "error": error})
+        LOG.warning("Failed to open csar URL: %(url)s due to error: %(error)s",
+                    {"url": url, "error": error})
         raise exceptions.VNFPackageURLInvalid(url=url)
 
 
@@ -73,10 +73,10 @@ def store_csar(context, package_uuid, body):
             context=context)
     except Exception as e:
         error = encodeutils.exception_to_unicode(e)
-        LOG.warn("Failed to store csar data in glance store for "
-                 "package %(uuid)s due to error: %(error)s",
-                 {"uuid": package_uuid,
-                 "error": error})
+        LOG.warning("Failed to store csar data in glance store for "
+                    "package %(uuid)s due to error: %(error)s",
+                    {"uuid": package_uuid,
+                    "error": error})
         raise exceptions.UploadFailedToGlanceStore(uuid=package_uuid,
                                                    error=error)
     finally:
diff --git a/tacker/hacking/checks.py b/tacker/hacking/checks.py
index f6d829d61..00a7e584d 100644
--- a/tacker/hacking/checks.py
+++ b/tacker/hacking/checks.py
@@ -46,3 +46,16 @@ def validate_log_translations(physical_line, logical_line, filename):
     msg = "N320: Log messages require translations!"
     if log_translation.match(logical_line):
         yield (0, msg)
+
+
+@core.flake8ext
+def no_log_warn(logical_line):
+    """Disallow 'LOG.warn('
+
+    Use LOG.warning() instead of Deprecated LOG.warn().
+    https://docs.python.org/3/library/logging.html#logging.warning
+    """
+
+    msg = ("T301: LOG.warn is deprecated, please use LOG.warning!")
+    if "LOG.warn(" in logical_line:
+        yield (0, msg)
diff --git a/tox.ini b/tox.ini
index 2d71d0195..42fb774fd 100644
--- a/tox.ini
+++ b/tox.ini
@@ -130,6 +130,7 @@ import_exceptions = tacker._i18n
 [flake8:local-plugins]
 extension =
    N320 = checks:validate_log_translations
+   T301 = checks:no_log_warn
 paths = ./tacker/hacking
 
 [testenv:config-gen]