The histopathologic characters of gastric mucosa with aging are the loss of gastric glands at lamina propria and their replacement with hyaline-like connective tissue. The rate of glandular parenchyma in aged group was higher than that of non-aged adults, but there were no statistical difference of the parietal cell numbers between the two groups. The incidence of atrophic gastritis increases in elderly subjects, and the gastric acidity decreases with atrophy. However, aging is not the only cause of reduced gastric acid secretion; it has no effect on gastric hydrogen ion activity at fasting state. Reports about proton pump inhibitor (PPI) and clopidogrel combination treatment are still controversial. The observation of 109 octogenarian patients in China showed that PPI had no side effect on the clinical therapy when combined with clopidogrel. The shortages of the study are the limitation of case number and shorter treatment duration. Helicobacter pylori (Hp) infection plays a critical role in the development of some gastric diseases, especially atrophic gastritis and intestinal metaplasia. Histological changes of aging patients after H. pylori eradication indicated that inflammation was significantly improved compared with the patients without Hp eradication, with the improvement rate of chronic inflammation at 87.4%, and the improvement rate of acute active inflammation at 57.8%, respectively.