diff --git a/src/main/java/info/istlab/ServerTester/MulticastReceiver.java b/src/main/java/info/istlab/ServerTester/MulticastReceiver.java
index 534d812..a1c92fe 100644
--- a/src/main/java/info/istlab/ServerTester/MulticastReceiver.java
+++ b/src/main/java/info/istlab/ServerTester/MulticastReceiver.java
@@ -13,6 +13,7 @@
     Thread thread;
     MulticastSocket socket;
     MulticastSender sender;
+    RemoteHostsWindow remoteHostsWindow;
 
     // 受信したデータを IP アドレスをキーにして保存
     Hashtable<String, String> receivedData = new Hashtable<String, String>();
@@ -28,6 +29,7 @@
         thread = new Thread(this);
         thread.start();
         sender = new MulticastSender(portNum);
+        remoteHostsWindow = new RemoteHostsWindow(receivedData);
     }
 
     public void run(){
@@ -43,9 +45,12 @@
             }
             String addr = packet.getAddress().getHostAddress();
             String message = new String(packet.getData(), 0, packet.getLength());
-            receivedData.put(addr, message);
 
-            System.out.println(addr+"からの受信: " + message);
+            receivedData.put(addr, message);
+            if (remoteHostsWindow != null) {
+                remoteHostsWindow.updateData(addr, message);
+            }
+            // System.out.println(addr+"からの受信: " + message);
         }
     }
     public void stop(){
@@ -59,6 +64,10 @@
             JOptionPane.showMessageDialog(Host.mainhost, "受信したデータがありません。", "受信データなし", JOptionPane.WARNING_MESSAGE);
             return;
         }
-        new RemoteHostsWindow(receivedData);
+        if (remoteHostsWindow != null) {
+            remoteHostsWindow.setVisible(true);
+        } else {
+            remoteHostsWindow = new RemoteHostsWindow(receivedData);
+        }
     }
 }
diff --git a/src/main/java/info/istlab/ServerTester/RemoteHostsWindow.java b/src/main/java/info/istlab/ServerTester/RemoteHostsWindow.java
index 4244704..6404302 100644
--- a/src/main/java/info/istlab/ServerTester/RemoteHostsWindow.java
+++ b/src/main/java/info/istlab/ServerTester/RemoteHostsWindow.java
@@ -1,5 +1,6 @@
 package info.istlab.ServerTester;
 
+import java.awt.BorderLayout;
 import java.awt.Color;
 import java.awt.Desktop;
 import java.io.IOException;
@@ -16,14 +17,14 @@
 import javax.swing.JTabbedPane;
 
 public class RemoteHostsWindow extends JPanel {
-
+    JTabbedPane tabbedPane;
     public RemoteHostsWindow(Hashtable<String, String> receivedData) {
         JFrame frame = new JFrame();
-        frame.setTitle("Remote Hosts (自動更新はしません)");
+        frame.setTitle("Remote Hosts");
         frame.setSize(300, 200);
         frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
 
-        JTabbedPane tabbedPane = new JTabbedPane();
+        tabbedPane = new JTabbedPane();
         frame.getContentPane().add(tabbedPane);
         Iterator<String> it = receivedData.keySet().iterator();
         while (it.hasNext()) {
@@ -35,6 +36,14 @@
         frame.pack();
         frame.setVisible(true);
     }
+
+    public void updateData(String addr, String value) {
+        JPanel panel = (JPanel)tabbedPane.getComponentAt(tabbedPane.indexOfTab(addr));
+        panel.add(new RemoteHostPanel(addr, value), BorderLayout.CENTER);
+        tabbedPane.validate();
+        tabbedPane.repaint();
+        System.out.println("Tab updated "+addr);
+    }
 }
 
 class RemoteHostPanel extends JPanel {