Abstract: We have worked out quite a few pollens and spores from the commonly spore pollen poor loess,and first plotted some concentration pollen-spore diagrams of the loess strata.The evolution of vegetation and the corresponding climate in time and space in the region has been brought to light by an analysis of the variation of pollen-spore assemblages in many seetions.There are three interstadials,warmmer than present and two cooler stadials in the Last Interglaciation.They are correlated with the substages 5a,5b,5c,5d and 5e of the deep sea oxygen isotopic curves.The climate in the stadials was severely cold,with a mean annual temperature 14℃ lower than the present.The climate in the interstadials was relatively warmer,with a mean annual temperature 3-9℃ lower than the present.The temperature in the stadials of the Last Interglaciation was the same as that in the interstadials.The temperature in the interstadials was 1-3℃ higher than the present.It is know by comparing the pollen-spore cliagrams from ten sections in the Loess plateau,that,the change of vegetation in time is very similar,This implies that they were controlled by the same global climatic change.But the vegetation may vary from place to place due to change of local natural environment.The paleotemperature curve is reconstructed from the variation of vegetation during the Late Pleistocene.