The occurrence of the Quaternary in Sanhu area of Qaidam Basin, which has trapped the largest biologic gas field, is the product of migration of basin depositional center from west to east under the tectonic movements at the end of Tertiary. In recent years, lithologic gas reservoirs have been found in this area and been divided into three types including sand updip pinch-out, sand lens and sand property change in the lateral direction. The distribution regularities of lithologic gas reservoirs in the Sanhu area are summarized as distribution in the northern slope, development on the tectonic background, location below the marker bed k9, accumulation in thin sandstone and limitation to a certain depth. At last, according to the distribution regularity of lithologic gas reservoir, the authors point out favorable exploration areas of lithologic gas reservoir. This study has important theoretical and practical significances for lithologic gas reservoirs exploration in the Sanhu area of Qaidam Basin.