Abstract: Prydz Bay is a typical area of ocean carbon research in the Sourthern Ocean. It is also a key research area in Chinese National Antarctic Research Expedition (CHINARE). We comprehensively expounded the carbon cycle characteristics in the Prydz Bay by primary productivity, nutrient, chlorophyll, air - sea CO₂ flux, particle organic carbon (POC) export flux from the euphotic zone and net community productivity (NCP). The efficiency of the biological pump and the sea ice processes are the main influence factors of the carbon uptaking of Prydz Bay. Generally, awarding to the carbon cycle parameters, the Prydz Bay could be divided into the inside and outside regions and the carbon cycling characteristics are obvious diverse.The inside area is a high productivity area in the Southern Ocean, in which the carbon cycle processes are active. However, the outside area shows a high nutrient, low chlorophyll (HNLC) characteristics, which may be caused by the iron limited. In general, all parameters including dissolved organic carbon (DOC), POC, nutrient, chlorophyll-a (chl-a) and CO₂ partial pressure  (pCO₂) shows a general increasing or decreasing distributions with latitude variation. The carbon cycle mainly seriously affected by the advance and retreat of the sea ice. In the summer, the increasing biological productivity in the surfaceprimary resulted from the ice alage released and the stability of water column enhanced after the ice retreated. Overall, the carbon cycle of the Prydz Bay commonly controlled by the biological physical processes and their coupling effect, which has important implications for the carbon cycle mechanism research in the southern ocean.

Key words: Prydz Bay, carbon cycling, carbon flux, carbon uptaking dynamics, sea ice processes