Abstract: This paper expounds the characterization of forming carbonate rock during evolution from Hetaoyuan Fm in the central area of Biyang sag to Sodo Lake, conditions of sedimentary facies, sedimentation model as well as mother material of oil source in carbonate rock, oil source rock, resource quantities, reservoirs, reservoir space ets, and points out new area and potential reservoirs of the progressive exploration and development in the oil fields.