SUMMARYBackground: Long-term evaluation of gastric pathology after H. pylori infection is very important in order to reveal its clinical implications, since debate still exists on the gastric carcinogenesis provoked by H. pylori infection in animal models. Aim: Either to evaluate the long-term outcome of H. pylori infection or to determine how H. pylori could provoke gastric cancer in the mice model. Methods: Four-week-old specific pathogen free C57BL/6 mice (n ¼ 115) were infected with SS1, the mouseadapted H. pylori strain. After 4, 8, 16, 24, 36, 50 and 80 weeks of bacterial infection, the H. pylori-infected mice were sacrificed. Results: After 80 weeks of infection, almost all the H. pylori-infected mice developed hyperplastic gastritis,