Abstract: The structure of bacterial communities in intestinal flora of Trichiurus haumela was studied using high-throughput sequencing technology.As a result,a total of 36,129 valid sequences were obtained,and clustering to 245 OUTs.Except for 4 sequences (0.01%) could not be species classified,the rest belonged to 16 phyla,including 77 families,127 genera.At the level of phylum,Proteobacteria was overwhelmingly dominant with high relative abundance up to 52.30%,followed by Firmicutes (30.66%).At the level of genus,Photobacterium (47.90%) of Vibrionaceae (49.38%) and Candidatus_Arthromitus (17.04%) of Clostridiaceae_1 (25.40%) were the main genera.Alpha diversity analysis showed that,the OTU dilution curve flatten out gradually,and the Good's Coverage index was 100%,while the sequencing depth was large enough.