Abstract: Bacterioplankton is an important part of the marine microbial loop, playing a role in maintaining the stability of the marine ecosystem and material circulation. This paper summarizes the community composition of bacterioplankton and its influencing factors in different parts of the Southern Ocean. The results show that the dominant groups are α-proteobacteria, γ-proteobacteria, and Cytophaga-Flexibacter-Bacteroides (CFB), while less abundant groups exhibit strong spatial variability. Temperature and dissolved organic carbon concentrations are two of the main environmental factors that regulate the community structure. There is an obvious interaction between bacterioplankton and other compnents of the microbial food web. Environmental changes such as increasing water temperature and ocean acidification caused by climate change may affect the bacterioplankton community. In the future, research on the bacterioplankton in the pelagic waters, pack ice zone, and deep waters, should be strengthened. In addition, research on seasonal community changes in nearshor waters should be conducted, as should attempts to predict the potential changes and regulation mechanisms of the bacterioplanktonic community in the Southern Ocean via both field investigations and modeling.

Key words: Southern Ocean, bacterioplankton, community structure, seasonality, environmental factors