Dabusun lies in the Dabusun subbasin in the central Qarhan Playa. It is one of the many saltwater lakes in the endorheic Qaidam Basin, bound by the Qilian Mountains to the north, the Altun to the west, and the Kunlun to the south. Lying at an elevation of above sea level, it has a mean annual temperature of despite lying on the same latitude as Greece, Algeria, and Virginia in the United States. Dabasun is the largest present lake in the Qarhan Playa. It is fed by the main course of the Golmud River from the south and, to a lesser extent, by mineral springs from the north. In Qaidam's hyperarid climate, there is generally only of annual rainfall but about of annual evaporation. Its area is thus variable by season and year, usually but increasing in the wetter winter and spring and decreasing through the summer and fall. The lake is elongated, stretching from the northwest to the southeast. Its length is usually about east to west, and its width is usually about north to south. The maximum depth is , and the average depth varies from .