Objective To investigate the correlations between pathological changes and helicobacter pyloriinfection，serum pepsinogen and gastrin⁃17 of chronic atrophic gastritis（CAG）. Methods 127 patients with CAGwere enrolled in the study. Their serum levels of PGI，PGII，G ⁃17 and Hp were detected by 14C⁃UBT test andELISA. ROC curve was drawn to evaluate its diagnostic value. Results The infection rate of Hp was higher，andthe serum levels of PGI，PGII，PGR and G⁃17 decreased in the CAG group. The more severe the gastric mucosa at⁃rophy was，the more remarkably the serum levels of PGI，PGII，PGR and G⁃17 decreased. Moderate inflammationand moderate atrophy were predominant in the Hp ⁃infected patients. The area under the ROC curve of CAG was0.981，0.795，0.800 and 0.661 by PGI，PGII，PGR and G⁃17，respectively. Conclusion The combined test ofHp，PG and G⁃17 can improve the affirmative diagnose of atrophic gastritis，and it helps to stratify the atrophy riskand make early diagnosis of gastric mucosa atrophy.