Studying on fault system of base is favor of finding out the rules of forming and distributing of oil-gas.On the base of analyzing of the distributing feature and structure type of fault system in Bamianhe ramp,its affect on the elements of reservoir formation,such as hydrocarbon source rock,reservoir,conducting system,traps and so on,was discussed.The fault system,which composed of ones tilting toward basin and reserving toward basin,distributed as a whole along North-East and East-West in the plane.