Twenty-four fermented seafood （shrimp paste， crab sauce， Yucha） were collected from Li nationality in Hainan province， and microbial diversity were analyzed by conventional culture method and 16S rRNA sequencing analysis. It showed that the 180 identified strains of bacteria belonged 20 species from 5 genera. The lactic bacterial consisited of Lactobacillus （89.4%）， Pediococcus （3.9%）， Staphylococcus （3.3%）， Enterococcus （1.7%） and Weissella （1.7 %）. It was obvious that Lactobacillus was the dominant genus of fermented seafood， with Lactobacillus plantarum and Lactobacillus fermentum were dominant species. Also， the 16S rRNAV3-V4 was used as the target sequence to analyze the microbial community characteristics of 9 fermented seafood samples by Metagenomics Sequencing. The percent of Lactobacillus， Pediococcus， Weissella， Caproiciproducenss， Bacillus were 18.5%， 9.91%， 9.53%， 8.37%， 4.17% respectively in 9 samples with the most abundant microbial diversity. There was a significant difference in microbial communities between crab sauce and Yucha. The results of study revealed abundant microbial diversity and community structure in fermented seafood of Li nationlity in hainan， which was the basis for the use of tropical beneficial microbial resources.