Abstract: The baisc features such as the types of accumulative spaces，the distribution in vertical direction，and the main controlling factors and diagenesis are probed in detail and the favorable reservoir distribution is predicted based on core analysis data，conventional physical property data and well log information of Jurassic Lianggaoshan Formation，central Sichuan Basin.Research indicates the reservoirs are mainly distriduted in Lianggaoshan I and Ⅱsections of upper Lianggaoshan Formation.The thickness of sandbodies is uneven and goes thinner laterally from east to west.The sandbodies are the ones of sand bars and sand beach when lacustrine facies deposited.The prosity and permeability of the reservoirs are generally low with well developed fractures，the reservoirs are ultra-low prosity and tight ones.The sand reservoirs of Lianggaoshan formation are dominated by pore-fracture types with locally existing fracture-pore type.

Key words: Nanchong structure, Lianggaoshan Formation, sandbodies, reservoir, Sichuan Basin, tight