Abstract: Because of the limitation of information, the Su?2 structural model for southwest depression in Tarim basin is of multiple solutions, which directly affects the exploration potentials of Su?2 structure. Combining with previous research results and geological outcrop,seismic and drilling data, the model for this area is developed, from which the following understandings are obtained: piedmont fault belongs to basement?involved fault, the fault occurrence appears transition from piedmont to basin and from deep to shallow, gradually, the older strata like Devonian system are overlying on Su?2 anticline; the Lower Cretaceous is likely to exist in Su?2 structure, also there possibly exists the Jurassic