We　give　an　approach　on　the　detection　and　restraint　of　agent　ability　declaration　deception　in　multi-agent　system,　and　give　a　measure　to　detect　and　restrain　the　agent　slandering　and　agent　associated-cheat;　we　also　give　a　method　to　recognize　the　agent　impostor　deception.　Simulation　test　shows　this　method　can　fully　detect　the　following　impostor　deception　behaviors:　an　impostor　falsely　evaluates　other　agent;　an　impostor　broadcasts　rumor　in　other　agent＇s　relationship　web;　an　impostor　cooperates　with　other　agents.　It　provides　a　solution　to　detect　and　restrain　agent　deceptions　in　multi-agent　cooperation.　©　2005　IEEE.