Based on the analyses of sporopollen assemblages,magnetic susceptibility,OSL dating of lake sediments from borehole ZK1 in Qingtu Lake,northwestern margin of the Tengger Desert,this paper reconstructs the vegetation features of each stage, discusses the vegetation assemblages and lake climate changes since the late Middle Pleistocene. It is indicated that Qingtu Lake experienced two stages of climate changes, dry-cold and warm-wet in the Middle Pleistocene,and warm-wet and dry-cold in the Late Pleistocene. Moreover,it is accorded with climate cycle characteristics of the last glaciation and the last interglacial in MIS. Meanwhile,Qingtu Lake experienced the evolutions of climate of the dry-cold and warm-wet in the Holocene.