Objective To study the endoscopic manifestations of moderate or severe chronic atrophic gastritis (CAG) related to their pathologic diagnosis.Methods The correlation analysis was done between gastroscopic manifestations and pathologic diagnosis of 49 patients with moderate to severe atrophic gastritis.Results Pathologic diagnosis of moderate to severe CAG and mild CAG were conducted in 33 and 10 cases respectively, among them, 27 cases with intestinal metaplasia (IM) and 30 cases with atypical hyperplasia. For moderate to severe CAG under gastroscopy compared with their pathologic diagnosis, the coincidence rate was 67 35%; 20 cases out of them, stained in vivo with methylene blue under gastroscopy, the coincidence rate of diagnosis was 80%. Compared with pathologic diagnosis, the gastroscopic manifestations of gastric mucosa have positive prediction rate more than 80%, when several alterations coexisted, positive prediction rate raised to more than 90%, but for every individual alteration, incidence of positive prediction was not significant. Both sensitivity and specificity of each manifestation under endoscopy were more than 95%. Other manifestations such as gastric mucosa thinning, their positive prediction rates of IM and atypical hyperplasia were less than 70%; their sensitivity and specificity were less than 30%. In using coarse and uneven lumped mucosa as the criteria in diagnosing IM and atypical hyperplasia, the sensitivity was 92 85% and 83 33% respectively, and the specificity was the same (about 70%).Conclusion Coincidence rate of diagnosis under gastroscopy and pathology is quite low in moderate to severe CAG, but the knowledge of gastroscopic manifestation and the staining technique might raise this coincidence rate.