Baise basin is a strike-slip basin formed in Early Paleogene,Southern China. Due to the uplift during the Quaternary time, multi-stage terraces developed along the Youjiang River, and accretionary red earth sediments occurred commonly in the basin, especially along the river terraces. As the typical sediments in Southern China, the red earth sediments are comparable to the loess-paleosol sequences in Northern China. Clay minerals are the most important components of red earth sediments, which are widely used as indicator of climate changes. With attention on global change research over the world, in recent years clay mineralogy of Quaternary sediments has become more and more attractive in reconstructing paleoclimate and paleoenvironmental evolution in terrestrial environment, and their effectiveness has been recognized by large numbers of researchers. To reconstruct the paleoclimate changes of the Baise basin,Southern China,clay mineralogy of the Dawang red earth sediments was investigated using ESR dating and X-ray diffraction (XRD) methods. The Dawang red earth section (23°51'47. 36"N, 106°39'25. 91"E) is located in Dawang Village of Youjiang District, Baise city, Guangxi Zhuang Autonomous Region. The profile can be divided into five layers from top to bottom, according to color, grain size, and the degree of tuberculosis of the sediments. Samples for analysis of clay mineralogy were collected at 10cm interval along the section, with a total number of 97 samples. The samples for ESR dating were collected at 1.5m, 5. 5m, and 9. 7m depth of the profile, and were determined to have the age of 10813ka, 39639ka, and 45945ka, respectively, in agreement with the occurrence of the third river terraces of the Youjiang River. XRD analysis shows that clay mineral compositions of the sediments are dominated by illite, kaolinite, and vermiculite (or hydroxy-interlayered-vermiculite),while a sharp change in relative contents of clay minerals occurs at ca. 0. 26Ma, suggesting increasing weathering, pedogenesis, and paleoclimate change from relatively dry/cold to warm/humid,which is comparable to the event of glacial to interglacial transition (0.26Ma B.P.,MIS 7.5) recorded by the magnetic susceptibility of fluvial-lacustrine sediments. In addition, the illite crystallinity of sediments changes from relatively stable in the lower to obviously fluctuant in the upper section, which indicate that paleoclimate changed from relatively dry/cold to warm/humid. The fluctuations of relative clay mineral contents in the red earth sediments indicate that the red earth section has experienced a multi-stage of sedimentary and weathering. It is typical accretionary red earth sediments in Southern China.