Abstract: Using seismic description technology can effectively distinguish the reservoir layer and the round layer on the certain geology condition,and we can describe the shape of reservoir layer(oil layer) visually. Using it to compute reserves, the accuracy of calculation can be increased.In Guantao FM of Xintan oil field, the oil layer is controled by structure and lithology. Horizontally it connecting the universality badly, change quickly, thickness of single layer is small. With the normal method of using the well data and structure bathymetric to define oil bearing area, quantity of geological reserves is not accurate. After using seismic description technology, we obtain a good result.