You can start the Edit Tool like thispublic void CurrentTool(IApplication app) { ICommandBars documentBars = app.Document.CommandBars; UID cmdID = new UIDClass(); cmdID.Value = "{9EBF3A1E-D0C0-11D0-802D-0000F8037368}"; ICommandItem cmdItem = documentBars.Find(cmdID, false, false); app.CurrentTool = cmdItem; }