Abstract: controlling roles of basinal fault can be div ided into the five classes: Class I fault controls the structural evolution and sedimentary develop-ment; Class II fault is as key boundary line for classification of the structural units and for controlling source rock provinces; Class III fault con-trols the formation and distribution of various structural traps; Class IV fault controls the development and evolution of local structural traps; andClass V fault is of destroy roles to the structural traps or make the structural traps complicated. There exist four types of faults or six originaltypes of faults, which control eight original types of structural traps, in which the most significant traps are fault-extending anticline, thruststructure and fault-slipping anticline ones. In the hinterland of this basin, there are developed fault structural belts with great hydrocarbon po-tentials and low extent of exploration efforts. The study shows that the trap belts with developed fractures in the center or surroundings of thesource rocks will be the most favorable targets for breakthrough of exploration.

Key words: Qaidam basin, fault, feature, control, origin