Abstract: TheMS80 Wenchuan，China，earthquake ruptured two large thrust faults along the Longmen Mountains thrust belt.Between them，the coseismic fault in Pengguan thrust belt created the second longest surface ruptures.In this paper，in order to distinguish the coseismic fault in Pengguan thrust belt，the fine interpretation of seismic profiles in the central Longmen Mountains have been accomplished by take advantage of geology map，drilling data and 2D/3D seismic reflection profiles，Our studies found that the Pengguan thrust belt have three main faults and another branch faults.The main faults are developing imbricated structure in the shallow strata and among them are developing the duplex.The coseismic fault which made the surface ruptures in the Pengguan thrust belt is the ③ fault，that is also the largest fault in the front of central Longmen Mountains.These faults are formed with flat and ramp and they are steep at the surface but the angle dip decreased with the depth increasing.Our studies indicated that these fault were generating in the Late Triassic period，developing in the Late Jurassic period and keeping on activity in the Cenozoic period.According to characteristics of geology，the main fault and the coseismic surface ruptures，the front of central Longmen Mountains can be divided into two subsegments，one is the Bailu area and the other is Hanwang area.The characteristics of shallow structures in the Pengguan thrust belt could provide some details and restriction for the research of faults in the front central Longmen Mountains.