Abstract: Xihu Trough is located at the east-northem East China Sea shelf basin, and Pinghu Forma tion (Eocene) is the key target in the basin. This paper gives lithological and depositional analyses to four main genetic oil/gas reservoirs of Pinghu Formation including tidal channel, tidal distributary channel, dis tributaly channel and mouth bar-front sheet sand, forecasts these reservoirs shape and makes a review on physital propenies of all reservoirs.