Abstract: The present paper deals with the application of the stratal slicing technique as a key technique in seismic sedimentology to the Sartu oil reservoirs from the Nengjiang Formation in the Songliao Basin. Numerous stratal slices for individual 3D seismic projects are constructed in the light of the refined interpretation of distinct sequence boundaries in the study area. These slices help clarify the distribution of the depositional systems in the Sartu oil reservoirs, and assist in the isochron analysis of favourable horizons and macroscopic delineament of the depositional systems. Of course the stratal slicing technique should be integrated with core examination and well logs so as to distinguish the depositional systems in precise terms.