Abstract: Shenghai G2 buried hill, a block buried hill, lies in the north of the Chengdao Oilfield, Bohai Bay basin. In order to analyze the reservoir characteristics and reshape the exploration and development of the buried hill, the authors studied systematically the stratum characteristics, storage space, reservoir development rules and controlling factors. The Paleozoic reservoir of Shenghai G2 mainly has secondary storage space, including intercrystal pore, dissolution aperture and fracture. Fracture is the main storage interspace among them. The main reservoir develops in the O₁y-O₁l and ∈₃ f. Layers on the top of buried hill and near the fault are advantaged reservoirs. The research results show that the weathering process, lithological characteristics, and faulting are mainly factors controlling the development extent of reservoirs. The conclusion has reference function to the exploration and development of buried hill in Chengdao Oilfield and Bohai Bay basin.