Objective To explore the abundance and species composition differences of intestinal flora in phlegm-dampness constitution people. Methods A total of 30 stool samples from phlegm-dampness constitution and 30 neutral constitution subjects were collected. The total bacterial DNA was extracted and quantified in the 2 groups. The Miseq library was constructed and the PE read length obtained by sequencing the Miseq sequencing was spliced according to the overlapping region relationship. According to different levels of similarity

operational taxonomic unit（ OTU） clustering analysis was performed on all sequences

and the community composition of each sample was counted at each classification level. 16 S rDNA sequencing technology was used to analyze the composition and abundance change of intestinal flora structure of the phlegm-dampness constitution and neutral constitution subjects.Results At the level of OTU

partial least squares discriminant analysis（ PLS-DA） showed that there was a significant difference in the composition of intestinal flora between the phlegm-dampness constitution and the neutral constitution; at the level of the phylum

the ratio of Bacteroides and Firmicutes in the phlegm-dampness constitution group was lower than that of the neutral constitution; at the genus level

the genus of the decreased relative abundance of phlegm-dampness constitution was mainly Bacteroides

Roche（ P < 0. 01）

Faecalibacterium and Megamonas

and the genus of increased relative abundance of phlegm-dampness constitution were mainly Dialister

Lachnoclostridium

Eubacterium rectale

and Dorea. Conclusion The intestinal flora of the subjects with phlegm-dampness constitution and neutral constitution is different in abundance and species composition

and the decreased ratio of Bacteroides and Firmicutes and the decreased relative abundance of Roche are the characteristics of the intestinal flora of phlegm-dampness constitution.