A microscopic examination of 1,000 cases of gastroscopic biopsy specimens revealed that the prevalence and severity of chronic gastritis, neutrophilic infiltration, and Helicobacter pylori infection increased with advancing age until the age reached about 40, but they decreased thereafter in accordance with the increasing prevalence of intestinal metaplasia. The prevalence and severity of Helicobacter pylori infection, chronic gastritis, and neutrophilic infiltration were proportionately related to each other and to gastric peptic ulcer, but inversely related with intestinal metaplasia and gastric carcinoma. The results suggested that chronic gastritis and gastric peptic ulcer may be associated with Helicobacter pylori infection and that if these lesions persist, intestinal metaplasia may develop with decreased severity of chronic gastritis and Helicobacter pylori infection but, instead, increase of the risk of gastric carcinoma. And it is thought that the cause of the high incidence of gastric carcinoma in Korea may be related to the fact that chronic gastritis and Helicobacter pylori infection develop earlier in life and therefore the prevalence of intestinal metaplasia is higher in Korea than in other countries.