///The Pingluoba structure of western State w:st="on">Sichuan is a buried structure in front of the Longmen Mountain over thrust structure. In this area, the braid delta-lake transitional facies on the arid and semi-arid climate condition are developed in the Middle and Upper Jurassic, the source of gas mainly comes from deep Xujiahe Formation, and the gas reservoir belongs to the typical “the secondary gas pool”. The study shows that the main controlling factors of the gas reservoir forming are preferential capturing of gas in the palaeo-structure which provides good conditions for early accumulation and succession development of gas, the quality sand body which is under control of sedimentary facies and provides pore space for gas accumulation, the fault offers the migration pathway for the cross formational flow of natural gas, and the fracture-developed system which decides the high production of producing pays.