Abstract: The Middle Jurassic Shaximiao Formation is a major exploration field for tight gas in Sichuan Basin, which has the characteristics of shallow burial depth, low investment and high benefits. At present, the core production area is focused in the Western Sichuan Basin. Therefore,it is urgent to systematically summarize the tight gas accumulation conditions of Shaximiao Formation at basin scale, so as to expand the exploration field. Based on the study of source rock, natural gas source and fault development of Shaximiao Formation, configurations of source rock and reservoir assemblage are analyzed in detail and gas accumulation patterns established of different regions in the basin, and favorable exploration targets are put forward. The results show that natural gas of the Middle Jurassic Shaximiao Formation in Sichuan Basin is jointly supplied by source rocks of the Upper Triassic Xujiahe Formation, Lower Jurassic Ziliujing Formation and Middle Jurassic Lianggaoshan Formation. From west to east, the natural gas is mainly coal type gas, oil type gas and mixed oil type gas-coal type gas. The gas accumulation patterns vary significantly among different regions due to the different geological conditions. For example, gas reservoir in Western Sichuan Basin is mainly a lower generation and upper storage type supplied by the Triassic source rock and communicated by reverse faults. In the Central Sichuan Basin, it is dominated by a self-generation and self-storage gas reservoir supplied by the internal Jurassic source rock and connected by normal faults. While in Eastern Sichuan Basin, it is mainly a self-generation and self-storage gas reservoir supplied by the Jurassic source rock and supplemented by a lower generation and upper storage type gas reservoir supplied by the Triassic source rock and communicated by normal faults. Among them, Shaximiao Formation in Western Sichuan Basin, northern part of Central Sichuan Basin and northern part of Eastern Sichuan Basin has relatively superior geological conditions for gas accumulation and relatively large exploration potential. At present, exploration degree is low in the northern part of Central Sichuan Basin, which is the key exploration area in the near future.