By means of surface and subsurface geological combination research, the authors use the organic and inorganic geochemistry to describe the geological conditions of Lower Paleozoic gas formation and gas reservoir characteristics in the State w:st="on">Sichuan Basin, reveal mutual coupling relations between the destroyed oil pool and gas reservoir, and establish the model of Lower Paleozoic petroleum accumulation. Both lower Cambrian and lower Silurian are two sets of high-quality source rocks in the Sichuan Basin, with an average thickness of about 100 mother distributions show a significant inheritance, with three centers of hydrocarbon-generating intensity like as southern Sichuan, eastern Sichuan and western Hubei provinces. Several gas layers in the Lower Paleozoic sequence in the Sichuan Basin exist, including the middle-upper Cambrian Xixiangchi Formation, lower and Middle Ordovician Nanjinguan Formations and Baota Formations, and lower Shiniulan Formation (called Xiaoheba Formation in east Sichuan Basin).