Objective To investigate the relationship between helicobacter pylori（ Hp） infection and tongue coating flora in patients with chronic gastritis. Methods A total of 64 patients with chronic gastritis were divided into type I infection group（ 23 cases）

type Ⅱ infection group（ 20 cases） and non-infection group（ 21 cases） according to Hp test results. The distribution of thin white fur

thin yellow fur

thick white fur and thick yellow fur was compared between the groups. The samples of tongue fur were collected for 16 S rRNA gene sequencing. The structure of the bacterial phylum and bacterial genus of the flora were analyzed. Results The patients of type I infection group and type Ⅱ infection group were mainly thin yellow fur and thick yellow fur. The patients of non-infected group were mainly thin white fur. The difference between infected or non-infected groups was statistically significant（ P <0. 05）. The 16 S rRNA gene sequencing results showed that there were 7678 operational classification units and the total number of reading sequences was 7 956 779

indicating that the amount of data in this sequencing sample was sufficient

and the richness and uniformity of the species contained in the samples were reasonable. The difference of sequencing results among groups was not statistically significant（ P > 0. 05）. In the composition of the phylum level

the tongue fur flora was composed of six dominant bacteria: Bacteroides

Proteobacterria

Firmicutes

Actinobacteria

Fusobacteria

and Saccharibacteria. The actinobacteria in the type Ⅱ infection group were significantly lower than those in the non-infected group and the type I infection group

while the Fusobacteria was significantly higher than those in the non-infected group and the type I infected group（ P < 0. 05）. At the genus level

the abundance of the genus Ackerman

the genus Ruminococcus

the genus Bacteroides

the genus Pleurotus

and the genus Macromonas in the non-infection group were higher than that in the type I infection group and type Ⅱ infection group（ P < 0. 05）.There was no significant difference in the abundance of the genus between the type I infection group and the type Ⅱinfection group（ P > 0. 05）. Conclusion Hp infection can affect the composition of the tongue fur flora. Hp infection has a higher chance of thin yellow fur and thick yellow fur. Hp may have a copolymerization relationship with clostridium.