Abstract: The Kumukuli Basin, which is located in the east side of the Kunlun Mountains, has favorable petroleum-generating conditions but undetermined tectonic division. Through the operation of 1∶50 000 high-precision gravity and magnetic measurements in the basin, coupled with systematic analysis on relevant data and pre-collected physical property data, it was found that the basin has two density interfaces and one magnetic interface. Using gravity and magnetic data to quantitatively calculate the thickness of the Cenozoic strata in the basin and the buried depth of the three interfaces, this research found that the thickness of the Cenozoic strata is generally thin in the center, thick in the north and south, thin in the west and thick in the east. In combination of regional geology and geophysical data, a fault system of the basin was inferred and constructed with a total of 44 faults explained, including 17 NW and NW-trending faults, 14 near-EW faults, 9 NE-trending faults, and 4 north-south faults. The Kumukuli Basin was further divided into 13 level-Ⅲ tectonic units. On this basis, combined with the oil and gas geological research, the northern slope belt and the northern depression were supposed to be oil-gas exploration areas and three oil-gas prospects were delineated within the areas.