This　paper　proposes　a　thinking　of　analyzing　arc　energy　during　the　opening　process　of　the　AC　contactor.　It　is　controlled　by　an　intelligent　controlling　module　in　this　paper,　so　that　the　contact　can　be　opened　at　different　time.　Based　on　a　mass　of　experiments,　the　math　processing　on　waves　of　arc　voltage　and　current　are　executed　by　the　data　acquisition　system　to　calculate　the　energy　of　the　arc.　By　analyzing　the　rule　of　the　arc　energy　in　different　conditions,　the　best　controlling　area　during　opening　process　of　the　AC　contactor　are　studied　in　this　paper.　We　complete　the　breaking　experiment　verification　of　AC4　electrical　endurance　test　based　on　new　intelligent　AC　contactor.　Copyright　©　2009　by　International　Academic　Publishers　Ltd.