Abstract: Polar marine environments contain rich microbial resources, and their unique life characteristics and special mechanisms for adapting to extreme environments and ecological effects all have important scientific research significance and application development prospects. Reviewing research of China in the field of polar marine microorganisms in the past decade, major progress includes: (1) the revelation of unique structures and functions of microbial communities and the geographical characteristics of genes related to the DMS/DMSP cycle and cultivable bacterial genomes in the Arctic and Antarctic oceans; (2) the discovery of a new ecological function to resist predation by protozoa by metabolizing DMSP, a new temperature response mechanism, and a new metabolic pathway for chitin oxidation degradation of polar marine bacteria; (3) the revelation of a role of a phage in regulating polar marine bacterial populations; (4) the elucidation of catalytic mechanisms of a series of novel organic matter-degrading enzymes from polar marine bacteria and their application potentials; (5) the establishment of processes for preparing an extracellular polysaccharide from a polar marine bacterium and the evaluation of its application potential in fields such as medicine and food; (6) the isolation and identification of a series of polar marine bacterial taxa. These research findings have been published in internationally renowned journals such as Nature Microbiology, Nature Communications, Microbiome, and ISME Journal, elevating the level, impact and voice of China’s research on polar marine microorganisms. In the future, strengthening interdisciplinary research and the application of cutting-edge technologies will be the direction to further promote the development of polar marine microbiological research in China.

Key words:  marine microorganisms, functions, mechanisms, research progress, polar regions