diff --git a/shadowsocks-csharp/Data/cn.txt b/shadowsocks-csharp/Data/cn.txt
index 30f51f20..8d25b904 100644
--- a/shadowsocks-csharp/Data/cn.txt
+++ b/shadowsocks-csharp/Data/cn.txt
@@ -62,6 +62,8 @@ Change &Font=设置字体(&F)
 &Top Most=置顶(&T)
 &Show Toolbar=显示工具栏(&S)
 Log Viewer=日志查看器
+Inbound=入站
+Outbound=出站
 
 # QRCode Form
 
diff --git a/shadowsocks-csharp/View/LogForm.cs b/shadowsocks-csharp/View/LogForm.cs
index 5a83d96e..5a3dc703 100644
--- a/shadowsocks-csharp/View/LogForm.cs
+++ b/shadowsocks-csharp/View/LogForm.cs
@@ -108,6 +108,9 @@ namespace Shadowsocks.View
             TopMostMenuItem.Text = I18N.GetString("&Top Most");
             ShowToolbarMenuItem.Text = I18N.GetString("&Show Toolbar");
             Text = I18N.GetString("Log Viewer");
+            // traffic chart
+            trafficChart.Series["Inbound"].LegendText = I18N.GetString("Inbound");
+            trafficChart.Series["Outbound"].LegendText = I18N.GetString("Outbound");
         }
 
         private void Timer_Tick(object sender, EventArgs e)