diff --git a/heat/engine/resources/openstack/cinder/volume.py b/heat/engine/resources/openstack/cinder/volume.py
index 9ac9f21c42..764a7b655a 100644
--- a/heat/engine/resources/openstack/cinder/volume.py
+++ b/heat/engine/resources/openstack/cinder/volume.py
@@ -280,7 +280,8 @@ class CinderVolume(vb.BaseVolume, sh.SchedulerHintsMixin):
     def _create_arguments(self):
         arguments = {
             'size': self.properties[self.SIZE],
-            'availability_zone': self.properties[self.AVAILABILITY_ZONE],
+            'availability_zone': (self.properties[self.AVAILABILITY_ZONE] or
+                                  None),
         }
 
         scheduler_hints = self._scheduler_hints(
diff --git a/heat/tests/openstack/cinder/test_volume.py b/heat/tests/openstack/cinder/test_volume.py
index 4023b3a823..41f5f6ad01 100644
--- a/heat/tests/openstack/cinder/test_volume.py
+++ b/heat/tests/openstack/cinder/test_volume.py
@@ -1349,3 +1349,26 @@ class CinderVolumeTest(vt_base.VolumeTestCase):
         prg_attach = mock.MagicMock(called=False, srv_id='InstanceInActive')
         self.assertEqual(False, rsrc._attach_volume_to_complete(prg_attach))
         self.assertEqual('vol-123', prg_attach.called)
+
+    def test_empty_string_az(self):
+        fv = vt_base.FakeVolume('creating')
+        self.stack_name = 'test_cvolume_default_stack'
+
+        vol_name = utils.PhysName(self.stack_name, 'volume')
+        self.cinder_fc.volumes.create.return_value = fv
+        fv_ready = vt_base.FakeVolume('available', id=fv.id)
+        self.cinder_fc.volumes.get.side_effect = [fv, fv_ready]
+
+        self.t['resources']['volume']['properties'] = {
+            'size': '1',
+            'availability_zone': "",
+        }
+        stack = utils.parse_stack(self.t, stack_name=self.stack_name)
+        self.create_volume(self.t, stack, 'volume')
+
+        self.cinder_fc.volumes.create.assert_called_once_with(
+            size=1, availability_zone=None,
+            description=None,
+            name=vol_name,
+            metadata={}
+        )
diff --git a/releasenotes/notes/support-handling-empty-string-for-volume-az-22ad78eb0f931954.yaml b/releasenotes/notes/support-handling-empty-string-for-volume-az-22ad78eb0f931954.yaml
new file mode 100644
index 0000000000..e1b71be43f
--- /dev/null
+++ b/releasenotes/notes/support-handling-empty-string-for-volume-az-22ad78eb0f931954.yaml
@@ -0,0 +1,6 @@
+---
+fixes:
+  - |
+    Empty string passing in for volume availability_zone can be correctly
+    handled now. For this case, it's same as no AZ set, so the default AZ in
+    cinder.conf will be used.