Abstract: Based on experimental analysis of geochemical drilling coring in water flooded reservoirs,the geochemical properties and the reservoir parameters flooded characteristics have been made clear.Through parameters modeling of oil saturation,saturated hydrocarbon gas chromatography total peak area under two reservoir types of different water-flooded degree,the layer identification methods and evaluation criteria have been established,and a set of qualitative and quantitative calculation of the organic combination has been formed.Using this method,flooded layer evaluation of Nanpu Sag has been carried out.The results show that the water flooded degree of 7 wells in Nanpu sag coincide with the actual test oil wells flooded.The method is proved to be of strong adaptability and can provide a strong technical support for water flooded degree identification and evaluation in deep water injection development.