Abstract: The sedimentary system and facies typies in the third section of the Paleogene Shahejie Formation of Chang didistrict in the Zhanhua Sag have been studied by using the geolo gical,log,seismic and chemical analysis data.The authors consider that the main type of sedimentary facies was subsurface fan,which can be divided 3 types of subfacieses-root-fan,middle-fan and fan edge.The middle-fan can be divided 3 microf acieses-braided channel,space between channel and front-edge zone.Secondly,rock composition,micro-tex ture of pore,diagenetic stage and hetero geneity of the reservoirs have been systematically studied by comprehensive using granulometric analysis,reservoir capability,mercury penetration analysis,electronic microscope scanning,the digital processed achievements of log data and etc.At last,the authors point out the favorable sand bodies and reser voir beds-the upsides and middle part of the third member of the Shahejie Formation.