Abstract: Through analyzing the grain size characteristic of continental shelf surface sediments obtained during Chinese 24th and 29th South Pole Exploration in Prydz Bay，Southern Ocean to discuss the main factors influence sedimentation. The surface sediments are divided into nine types: G, msG, gM, gmS, (g)M, (g)mS, S, sZ, Z. The study area can be divided into two sections by sediment types and topography of the bay: gravelly mud section in east and gravelly sand section in west. In the eastern gravelly mud section, coastal current dominates sedimentation processes in Four Ladies Bank and Svenner Channel. In Prydz Channel and Amery Basin, Prydz Bay Gyre is the dominant factor controlling sedimentary processes. In contrast, icebergs are the primary factors influence sedimentation in front of Amery Ice Shelf and Fram Bank, while the influencing of current is weak.

Key words: Prydz Bay, surface sediment, grain size characteristic, environmental implication