diff --git a/neutron/services/segments/db.py b/neutron/services/segments/db.py
index 8c844fbcc04..af8f1489276 100644
--- a/neutron/services/segments/db.py
+++ b/neutron/services/segments/db.py
@@ -23,6 +23,7 @@ from neutron_lib.db import utils as db_utils
 from neutron_lib import exceptions as n_exc
 from neutron_lib.plugins import directory
 from oslo_concurrency import lockutils
+from oslo_config import cfg
 from oslo_db import exception as db_exc
 from oslo_log import helpers as log_helpers
 from oslo_utils import uuidutils
@@ -37,6 +38,26 @@ from neutron.objects import network
 from neutron.services.segments import exceptions
 
 
+_USER_CONFIGURED_SEGMENT_PLUGIN = None
+
+
+def check_user_configured_segment_plugin():
+    global _USER_CONFIGURED_SEGMENT_PLUGIN
+    # _USER_CONFIGURED_SEGMENT_PLUGIN will contain 3 possible values:
+    # 1. None, this just happens during neutron-server startup.
+    # 2. True, this means that users configure the 'segments'
+    #    service plugin in neutron config file.
+    # 3. False, this means that can not find 'segments' service
+    #    plugin in neutron config file.
+    # This function just load once to store the result
+    # into _USER_CONFIGURED_SEGMENT_PLUGIN during neutron-server startup.
+    if _USER_CONFIGURED_SEGMENT_PLUGIN is None:
+        segment_class = 'neutron.services.segments.plugin.Plugin'
+        _USER_CONFIGURED_SEGMENT_PLUGIN = any(
+            p in cfg.CONF.service_plugins for p in ['segments', segment_class])
+    return _USER_CONFIGURED_SEGMENT_PLUGIN
+
+
 class SegmentDbMixin(common_db_mixin.CommonDbMixin):
     """Mixin class to add segment."""
 
@@ -258,7 +279,8 @@ def _update_segment_host_mapping_for_agent(resource, event, trigger,
                                            context, host, plugin, agent,
                                            status):
     check_segment_for_agent = getattr(plugin, 'check_segment_for_agent', None)
-    if not check_segment_for_agent:
+    if (not check_user_configured_segment_plugin() or
+            not check_segment_for_agent):
         return
     phys_nets = _get_phys_nets(agent)
     if not phys_nets:
@@ -289,7 +311,8 @@ def _add_segment_host_mapping_for_segment(resource, event, trigger,
         return
     cp = directory.get_plugin()
     check_segment_for_agent = getattr(cp, 'check_segment_for_agent', None)
-    if not hasattr(cp, 'get_agents') or not check_segment_for_agent:
+    if not check_user_configured_segment_plugin() or not hasattr(
+            cp, 'get_agents') or not check_segment_for_agent:
         # not an agent-supporting plugin
         registry.unsubscribe(_add_segment_host_mapping_for_segment,
                              resources.SEGMENT, events.PRECOMMIT_CREATE)
diff --git a/neutron/tests/unit/extensions/test_segment.py b/neutron/tests/unit/extensions/test_segment.py
index 32f6b6797b5..192dd0a0167 100644
--- a/neutron/tests/unit/extensions/test_segment.py
+++ b/neutron/tests/unit/extensions/test_segment.py
@@ -81,6 +81,7 @@ class SegmentTestCase(test_db_base_plugin_v2.NeutronDbPluginV2TestCase):
         if not plugin:
             plugin = TEST_PLUGIN_KLASS
         service_plugins = {'segments_plugin_name': SERVICE_PLUGIN_KLASS}
+        cfg.CONF.set_override('service_plugins', [SERVICE_PLUGIN_KLASS])
         ext_mgr = SegmentTestExtensionManager()
         super(SegmentTestCase, self).setUp(plugin=plugin, ext_mgr=ext_mgr,
                                            service_plugins=service_plugins)
@@ -2531,3 +2532,40 @@ class TestSegmentHostRoutes(TestSegmentML2):
             self.assertIn(sub_res['gateway_ip'], gateway_ips)
             self.assertEqual(len(sub_res['host_routes']), 1)
             self.assertIn(sub_res['host_routes'][0], host_routes)
+
+
+class TestSegmentHostMappingNoStore(
+        test_db_base_plugin_v2.NeutronDbPluginV2TestCase):
+
+    def setUp(self):
+        driver_type.register_ml2_drivers_vlan_opts()
+        cfg.CONF.set_override('network_vlan_ranges', ['phys_net1'],
+                              group='ml2_type_vlan')
+        cfg.CONF.set_override('service_plugins', [])
+        super(TestSegmentHostMappingNoStore, self).setUp(
+            plugin='neutron.plugins.ml2.plugin.Ml2Plugin')
+        # set to None for simulating server start
+        db._USER_CONFIGURED_SEGMENT_PLUGIN = None
+        db.subscribe()
+
+    @mock.patch('neutron.services.segments.db.update_segment_host_mapping')
+    @mock.patch('neutron.services.segments.db.map_segment_to_hosts')
+    def test_no_segmenthostmapping_when_disable_segment(
+            self, mock_map_segment_to_hosts, mock_update_segment_mapping):
+        with self.network(
+                arg_list=('provider:network_type',
+                          'provider:physical_network',
+                          'provider:segmentation_id'),
+                **{'provider:network_type': 'vlan',
+                   'provider:physical_network': 'phys_net1',
+                   'provider:segmentation_id': '400'}) as network:
+            network['network']
+        mock_map_segment_to_hosts.assert_not_called()
+
+        host1 = 'test_host'
+        physical_network = 'phys_net1'
+        helpers.register_ovs_agent(
+            host=host1,
+            bridge_mappings={physical_network: 'br-eth-1'},
+            plugin=self.plugin)
+        mock_update_segment_mapping.assert_not_called()