Abstract: Sporo-pollen analysis in Qishan section shows that the change of vegetation and climate of the Late Pleistocene can be divided into six stages and thirteen sub-stages in the southeast part of the Loess Plateau. Three cold-dry stages and two temperate moist stages of last glacial period are named Qinjiazhai glacial staircase, Qishan glacial staircase, Potou staircase, Shangjiapo interglacial staircase and Yangjiawan interglacial staircase respectively. Forest-steppe consisting of Ulmus, Quercus and herb indicating cold and semiarid climate was dominant during glacial periods, and mean annual rainfall was 400-500 mm at that time. Deciduous broadleaf forest consisting of Quercus, Julans and Pterocarya etc. representing temprate moist climate prevailed during interglacial periods and interglacial staircases, and mean annual rainfall was 600-700 mm at that time.