Abstract:Based on the study of grain size and geochemistry of Quaternary standard boreholes adjacent to the geographical boundary between North and south of China, the paleoclimate change and sedimentary environment change in the Huaibei Plain since the Middle Pleistocene are discussed. The results show that the climate of the Middle Pleistocene in the Huaibei Plain experienced a general change from warm wet to dry cold in the frequent alternation of warm and wet and dry cold (warm and cool), which is in the same phase with the temperate monsoon climate change trend in the northern part of eastern China monsoon region, but in inverse phase with the paleoclimate evolution model in the middle and lower reaches of the Yangtze River and the source area of the Huai River controlled by the subtropical monsoon climate. In the late Pleistocene, the climate experienced dry and cold (i.e., warm dry cold dry cold), warm wet, and dry cold, but it was more similar to the climate evolution pattern in the middle and lower reaches of the Yangtze River and the source area of the Huai River, but was not consistent with the climate change pace from warm wet to arid in northern China. In the Holocene, the climate in the Huaibei Plain and in the South and north of China was warmer, and the precipitation response increased. Generally speaking, the sedimentary environment of GBK1 standard borehole in the Guo River Basin evolved from semi deep lake to shallow lake and lakeside Lake, and then contracted and disappeared in the middle Pleistocene, and evolved into flood plain or river; since late Pleistocene, it is mainly River and flood plain. The regional climate change of the Huaibei Plain has a positive response to global change on the whole. Perhaps because it is located at the edge of the geographical boundary between the north and the south of China, the regional climate of the Huaibei Plain is unique.