Abstract: The technique of precise description for oil pools was put forwards and developed in 1990s, aiming to describe the dynamic characters for the study on the precise geologic features of reservoirs with the increasing dynamic information form oil mining. It will finally provide a 3-D visualized and digitalized geological model for reservoir prediction. The Jingan Oilfield in Ordos basin was found in North Shaanxi Province, with reserves of hundreds million tons. Since the application of precise description technique in the main C-6 reservoir of the oilfield, the area has been developed in high efficiency for 9 years.