Abstract: Four type-I depositional sequences were recognized from the eleven depositional sequenees of the Permian in South China by former researchers. In this paper, we will describe the sediments on the basal boundary surfaces of type-I sequences and use the data about the lithefacies, geochemistry and evolution of organisms to analyze the relationships between the sediments and geological events. Study has found that native soils of ferralitic and/or bauxite clays, residual breccia of 1imestone with freshwater cements, paleosol, and paleokarst are extensively distributed on these boundary surfaces in different type-I sequences. The trace elements; such as B, V/Ni, Ga, and the stable isotopes of δ13C and 87sr86Sr changed obviously across the boundary surfaces. There are also apparent differences between the fossil assemblages, such as fusulinids, ammonites, brachiopods, conodonts existing at the end of previous HSTs and the beginning of later TSTs, suggesting that the extinction and recovery of marine invertebrates probably happened during the times represented by the gaps of type-I boundary surfaces. Volcanic sediments have been observed in some places on the basal boundary surface of S7. The sediments on the boundary surfaces of the type-I depositional sequences have important significance for understanding the related geological events. It has been demonstrated that sediments on the basal boundary surfaces of S1 and S7 probably were associated with the tectonic rising event, which was accompanied by some volcanic activity in the beginning of and controlled the falling of relative sea leve1. The sediments on the bases of S6 and S1I could be attributed primarily to the Ia scale falling of sea 1evel. Based on results of this study, we believe that the definition and content of the Chuanqian movement, which was first named in Guizhou-Guangxi provinces. Southwest China and could be recognized between S6 and S7, should be revised. We also suggest that different classification of depositional sequence should be used for different sedimentary basins of the Permian in South China. For example, the S1 is a type-I depositional sequence in the Permian of the Yangtze craton, but it could became a type-Ⅱ depositional sequence of the same age in the Cathayan craton.