Abstract: This paper determines the complicated sequence of the early Triassic Period faults in WestSichuan by the methods of fracture filling,carbon-oxygen isotope,sound emission,even temperature determination of wrap,etc,and studies the matching relation between the se-quence and the oilgas evolution.The length and breadth of the fault and their valid confin-
ing are comprehensively studied by many methods and data,such as fluid cahracter,layer stress,section of fault plane,ground survey in fault zone.In addition,the paper makes an area assessment and points out the areas of different confining conditions,providing direct basis for improving exploration benefit.

Key words: Fault, Early Triassic period, Secction of fault plane, Fluid, Layre stress, Assessment