The authors have studied depositional sequences and reservoir features of Jurassic basins in Northwestern China, and on the basis of outcrop observations, drill data and laboratory analysis, it is proposed that the Lower and Middle Jurassic consist dominantly of lacustrine and swamp coal-bearing clastic rocks, in which there are fluvial and deltaic sandstone reservoirs;the Upper Jurassic is represented by red and/or variegated clastic deposits. The Jurassic reservoirs are marked by mainly low-porosity and low-permeability clastic rocks with rich volcanic debris, and locally good sandstone reservoirs are developed. There is a good association of source rocks, reservoir rocks and cap rocks in the Jurassic itself.