Treeview

If you need at run time means create a New context Menu and handle it under Right click....

Another link
http://www.csharpkey.com/visualcsharp/sdimdi/contextmenu.htm

thanks but i need it at run time

1: Drag a contextMenuStrip from the toolbox onto your form (contextMenuStrip1) - This will appear in the ide bottom tray
2: Add some menu items as required and enter code
3: In treeview properties window select (contextMenuStrip1) at the ContextMenuStrip property