This paper analyzes the controlling factors of accumutatlng nyorocaruon auo superimposed Sichuan Basin experienced multitectonics, including the original hydrocarbon-generating conditions, developing characteristics of paleo-reservoirs, preservation conditions and structures etc. The result shows that there are seven sets of source rocks in Sichuan Basin. They are all source rocks prone to produce oil except Upper Permian Longtan Formation and Upper Triassic Xujiahe Formation. The total potential hydrocarbon generation in the basin is 4. 2631 × 10^15 m3 , with paleo- reservoirs occurred in multiple layers. Deep burial resulted in the thermal cracking of oil to natural gas. Preservation conditions are favorable, in particular, that of the Lower Triassic gypsum as an important regional caprock. Another important factor controlling oil and gas accumulation is the basin-mountain structure. The suddenly deformed basin-mountain structure has weak deformation in the basin, and the preservation conditions are not destroyed. This is favorable for the preservation and accumulation of oil and gas in Himalayan epoch. On the contrary, the preservation conditions in the gradually deformed basin-mountain structure are destroyed and not favorable for the preservation and accumulation of oil and gas. The main reason of oil and gas accumulations in Sichuan Basin is that there are abundant hydrocarbon source and good preservation conditions there. Except Sichuan Basin, there are also abundant hydrocarbon source in the wide areas of South China, but the areas with the Middle-Lower Triassic gypsum-salt caprocks are eroded, and the preservation conditions are poor. It is thus difficult to form large-scale oil and gas accumulations.