Objective： To explore the effects of H. pylori infection on gastric epithelial cell kinetics and the expression of apoptosis related genes. Methods：Ｏne hundred and thirty-seven persons were enrolled and biopsy／operation specimens were taken for H. pylori detection by culture and histological assessments. Apoptotic cells in the specimens were counted in situ by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling（TUNEL） method. Epithelial cell proliferation was detected by immunohistochemical analysis of the proliferating cell nuclear antigen（PCNA）. The expressions of apoptosis-related gene Bax， bcl-2， and c-myc were examined by immunohistochemistry in biopsy specimens of 30 patients with H. pylori-infected chronic superficial gastritis and 10 uninfected patients with chronic superficial gastritis. Results： Of 137 persons，104 showed positive H. pylori. H. pylori infected patients with GU， DU had significantly higher apoptosis／proliferation ratio than persons with normal mucosa（P ＜ 0.01）， and H.pylori（+） patients with CAG， gastric cancer had significantly lower apoptosis／proliferation ratio than persons with normal mucosa（P ＜ 0.01）. But there was no difference between H.pylori（+） patients with CSG and persons with normal mucosa（P ＞ 0.05）. Bax and c-Myc in H.pylori（+） chronic superficial gastritis were significantly higher expressed than that in H.pylori（-） chronic superficial gastritis（P ＜ 0.01）. The positive staining of Bcl-2 was not found both in H.pylori（+） group and H.pylori（-） group. Conclution： H.pylori may affect apoptosis through altering the expression of apoptosis-related gene Bax and c-myc with the result of imbalance between gastric epithelial apoptosis and proliferation， which might be one part of the pathogenetic mechanisms of H.pylori infection.