diff --git a/ryu/topology/event.py b/ryu/topology/event.py
index e7b682c9..d4b29b68 100644
--- a/ryu/topology/event.py
+++ b/ryu/topology/event.py
@@ -170,4 +170,24 @@ class EventHostAdd(EventHostBase):
     def __init__(self, host):
         super(EventHostAdd, self).__init__(host)
 
+
+# Note: Currently, EventHostDelete will never be raised, because we have no
+# appropriate way to detect the disconnection of hosts. Just defined for
+# future use.
+class EventHostDelete(EventHostBase):
+    def __init__(self, host):
+        super(EventHostDelete, self).__init__(host)
+
+
+class EventHostMove(event.EventBase):
+    def __init__(self, src, dst):
+        super(EventHostMove, self).__init__()
+        self.src = src
+        self.dst = dst
+
+    def __str__(self):
+        return '%s<src=%s, dst=%s>' % (
+            self.__class__.__name__, self.src, self.dst)
+
+
 handler.register_service('ryu.topology.switches')
diff --git a/ryu/topology/switches.py b/ryu/topology/switches.py
index 7264075a..5f14440e 100644
--- a/ryu/topology/switches.py
+++ b/ryu/topology/switches.py
@@ -868,6 +868,11 @@ class Switches(app_manager.RyuApp):
             self.hosts.add(host)
             ev = event.EventHostAdd(host)
             self.send_event_to_observers(ev)
+        elif self.hosts[host_mac].port != port:
+            # assumes the host is moved to another port
+            ev = event.EventHostMove(src=self.hosts[host_mac], dst=host)
+            self.hosts[host_mac] = host
+            self.send_event_to_observers(ev)
 
         # arp packet, update ip address
         if eth.ethertype == ether_types.ETH_TYPE_ARP: