1. College of Geoexploration Science and Technology, Jilin University, Changchun 130026, China; 2. Jilin Institution of Geophysics Exploration, Changchun 130012, China; 3. The 5 th Gold Detachment of Chinese People’s A rmed Police Force, X i’an 710100, China

Through the studies of potential field anomaly and the characteristics of its derivative in geophysical section from Suifenhe to Qixingzhen (DB3 for short) , 12 major fractures have been divided by using normalized total gradient method of gravity anomaly and its phase in wave-number domain, and the basement depth of basin has been computed by the method of linear inversion in frequency domain. The authors also divided the area of Suiyang uplift, Dunmi subsidence, Muling uplift, Jixi Basin, Nadanhada uplift, Boli Basin, Qitaihe uplift, Beixing depression and Qixingzhen uplift, and the depth of the gravity floor is 0.9 to 3.8 km. Based on the gravitational and mag-netotelluric data, the authors analyzed nine structural divisions of the section and interp reted there are three promising areas of gas-oil potential in Dunmi subsidence, middle Jixi Basin and southern Boli Basin.