Five seawater samples were collected near Zhongshan Station during the 34th Antarctic Expedition from China,through Illumina high-throughput sequencing, the microbial composition and microbial community structure were identified.At the phylum level, Proteobacteria and Bacteroidetes were the most abundant, followed by Cyanobacteria.Flavobacterium and Psychrobacterwere dominant genera, each of them exceeded 20%. The genus UBA1315 was found for the first time in Antarctic seawater, and the function annotation results showed that there are abundant DNA repair genes in the seawater microorganism, which suggested that it might be helpful to adapt to the harsh environment.By comparison of the microbial community structure between Zhongshan Station and the upper waters of the Ross Sea,the results showed that the microbial diversity is higher in Ross sea upper water,and the abundance of the bacterial is different.In the Antarctic and Arctic seawaters, Proteobacteria,Bacteroidetes and Cyanobacteria are ubiquitously and abundantly present. Proteobacteria is the dominant phylum of waters from both polar regions, and Cyanobacteriais is most abundant in the Southern Ocean. This study has preliminarily revealed the microbial composition of the seawater near Zhongshan Station, and provided some basic data for further research on marine microbial resources investigation and development of Zhongshan Station in Antarctica.