Abstract: ZST structure, in south of Pinghu area, is a NNW trending reverse dragging semi-anticline occurred in Pinghu fault subsiding block. Existing research has revealed that the sandstone of Pinghu Formation has favorable reservoir-forming conditions and reservoir area is controlled by the gulf background such as gulf-wad depositional system in intertidal zone and subtidal zone. But because of boreholes are few, the cognition is weak now. Based on vast boreholes and core data, the reservoir is composed of lit hie arkoses, which belongs to middle porosity and middle permeability sandstone reservoir. Casting thin sections, scanning electron microscope and X ray diffraction show that reservoir properties of Pinghu Formation is influenced by sedimentary environment and diagenesis. Reservoir properties are controlled by the sedimentary environment. Channel facies and sand flat of intertidal zone and subtidal zone are good reservoirs. The diagenesis plays a critical role in the quality of reservoir properties. Cementation breaks the reservoir properties, while dissolution improves it.