Dear angelboy
You should set 'ToolboxBitmapAttribute' attribute on your control class like below :
[ToolboxBitmapAttribute(typeof(UserControl1), "images.myicon.ico")]
Another method is to place your desired icon (16 * 16) with exact name of your control in same project folder that your control exists.
Also I suggest you to take a look at this MSDN article
http://msdn.microsoft.com/msdnmag/is...-TimeControls/