Abstract: Shen 84-An 12 block of Damintun depression in Liaohe oilfield,as a complicated fault-block reservoir,has enteredinto the high water cut stage of middle-later period of oilfield development. In the guidance of classic sequence stratigraphy theory and analytic method of genetic sequence stra-tigraphy,and on the reference of high-resolution sequence stratigraphy principle,using drilling,logging,seismic data in Shen 84-An 12 block,this paper accurately identified thesequence symbol characteristics of drill sequence boundary,seismic sequence boundary,flooding surface and base-level cycle,studied the relation between the rise and decline ofbase-level and sand rock distribution. The study has shown that sandbody usually appear to be closely-contact zone when A/S<1,and whileA/S>l,the sand body is less de-veloped,small scale and small contact area in the sedimentary region,especially when A/S is large,sandbody appear to be isolated,which has furtherly proved the extensive appli-cation prospect of high-resolution sequence stratigraphy in the oil field development.