Objective: To explore the distribution of syndrome elements and differences in gut microbiota in patients with chronic gastritis with yin deficiency syndrome, and provide reference for clinical diagnosis of chronic gastritis patients. Method: A total of 52 patients with chronic gastritis with yin deficiency syndrome were collected, including 35 patients with chronic atrophic gastritis (CAG) with yin deficiency syndrome, 17 patients with chronic non atrophic gastritis (CNAG) with yin deficiency syndrome, and 31 healthy individuals. Using the method of syndrome differentiation to analyze the differences in the distribution of syndrome elements between CAG and CNAG with yin deficiency syndrome, and using the 16S rRNA high-throughput sequencing method to detect gut microbiota, identify differential bacterial communities, and analyze the relationship between the distribution of syndrome elements in CAG and CNAG with yin deficiency syndrome and the differences in gut microbiota. Result: (1) Distribution of syndrome elements: The common disease locations and syndrome elements of CAG Yin deficiency syndrome are stomach, liver, and spleen; The common and miscellaneous syndrome elements include heat, qi stagnation, phlegm, dampness, food accumulation, qi deficiency, yang deficiency, and yang hyperactivity. The common locations and elements of CNAG Yin deficiency syndrome are stomach, liver, and spleen; The common and miscellaneous syndrome elements include heat, qi stagnation, phlegm, dampness, food accumulation, qi deficiency, blood deficiency, and yang deficiency. There was no significant difference in the distribution of syndrome elements at different locations between the two groups; In the comparison of points, the phlegm syndrome element (P<0.05) has statistical significance in the analysis of concurrent and miscellaneous disease syndrome elements. (2) Species composition: At the genus level, compared with the healthy group, the abundance of CAG Yin deficiency group in the genera Porphyromonas and Actinobacteria increased significantly (P<0.01); In the genus Peptonophilus and Eubacterium_ Hallii_ The abundance of group bacteria increased (P<0.05); The abundance of CNAG Yin deficiency group significantly increased (P<0.01) in Porphyromonas and Peptone loving bacteria, and increased (P<0.05) in Actinobacteria_ The abundance of bacterial genera UCG010, UCG003, and butyric acid bacteria decreased (P<0.05). Compared with the CAG Yin Deficiency group, the CNAG Yin Deficiency group showed a significant decrease in the abundance of mucinous true bacteria (P<0.01); The CAG Yin deficiency group showed significant enrichment in the abundance of anaerobic bacteria, fecal bacteria, and butyric acid bacteria compared to the CNAG Yin deficiency group (P<0.05). LEfse analysis obtained a total of 17 biomarkers, including 4 in the CAG yin deficiency group, 11 in the CNAG yin deficiency group, and 2 in the healthy group. Conclusion: There are differences in the distribution of syndrome elements between CAG and CNAG yin deficiency groups, as well as differences in the diversity and abundance of specific gut microbiota. The imbalance of gut microbiota is closely related to the development of chronic gastritis.