Abstract: The climatic significance of clay mineral composition is discussed in this paper based on the ¹⁴C dating and clay mineralogical data of the Core ANT29-P4-03 taken from the northwest side of the Prydz Bay. The abundance of clay minerals are in an order of illite > smectite > kaolinite > chlorite. Smectite is mainly derived from igneous rocks and was higher during the periods of 26.0~26.5ka,25.3~25.6 ka,25.0 ka,and 16.5~17.0 ka. It means that the content of smectite was high in glacial periods,but low in inter-glacial periods. Illite and kaolinite mainly came from the Prydz Bay shelf. The higher the content of Kaolinite,the more humid the climate would be. Illite,on the other hand,indicates a colder and drier climatic condition. In general,illite and montmorillonite dominated the core,therefore,the entire core was formed in a relatively cold and dry environment.