〔Abstract〕 Objective To investigate the correlation between OLGA and OLGIM staging system and serum pepsinogen(PG) concentrationin patients with chronic atrophic gastritis(CAG), and to analyze the incidence of gastric cancer and its risk factors during follow-up. Methods Endoscopic monitoring was performed on patients who were previously diagnosed as chronic atrophic gastritis(CAG) and were pathologically confirmed to be in line with gland atrophy with or without intestinal metaplasia(IM) and low-grade intraepithelial neoplasia(LGIN). Follow-up patients were endoscopied and biopsied according to the new Sydney system biopsy standards for histological examination,according to the histological results,OLGA and OLGIM staging were performed. Stage 0 to II were low risk of gastric cancer,and stage Ⅲ to Ⅳ were high risk of gastric cancer. Serum pepsinogen and gastrin-17 were measured with ELISA methods at the same time. Results 164 patients with atrophic gastritis were enrolled,averaging age of( 57. 48 ± 10. 71) and male/female 102/62. All patients had been diagnosed with gastric mucosal atrophy with or without intestinal metaplasia and low-grade intraepithelial neoplasia,and the mean follow-up time was( 4. 2± 3. 3) years at least two endoscopic follow-ups were performed. Compared with the low-risk groups with OLGA stage and OLGIM stage,G-17 was significantly increased in the high-risk group,PGI and PGR were significantly decreased,and the difference was statistically significant( P<0. 05). During the follow-up,6 cases of gastric cancer were detected( 3. 65%),and 4/2 were male/female. Among them,there were 5 cases of early gastric cancer and 1 case of advanced gastric cancer,and the tumor progression rate of chronic atrophic gastritis was0. 58% annually. COX regression analysis showed that patients older than 60 years old with atrophic gastritis and low-grade intraepithelial neoplasia were risk factors for the prediction of gastric cancer of atrophic gastritis. Conclusion Chronic atrophic gastritis is a precancerous condition of gastric cancer,and endoscopic follow-up is helpful for early detection of gastric cancer. For patients over 60 years old with severe atrophic gastritis and low-grade intraepithelial neoplasia,it is recommended to reexamine high-definition gastroscopy every 1-2 years.