Objective The purpose of this study was to investigate the relationship between Helicobacter pylori (H. pylori) infection-induced changes in gastric mucosal immune cells and glandular epithelial cell damage and the histopathological characteristics of these changes. Methods We performed a detailed histomorphometry and immunohistochemical analysis of a total of 1635 H. pylori-infected gastric mucosal specimens. Results Stage-wise features were as follows: Early stage of infection: H. pylori was colonized in the mucous layer, and very few neutrophils were visible in the layer. Gastric surface epithelial cell infection stage: H. pylori specifically and selectively adhered to the cytoplasm of the surface mucous cells, with the presence of a small number of neutrophils, eosinophils, and lymphocytes infiltration, which is termed early immune response. Compensatory mucous neck cell hyperplasia stage: proliferation of stem cells in the deep gastric pit and infiltration of a large number of lymphocytes in the superficial layer of lamina propria were observed, which is termed immune cell mobilization counterinsurgency. Lamina propria lesion stage: excessive upward migration of the proliferative area. Infiltration of a large number of lymphocytes, plasma cells, monocytes, macrophages, and other immune cells was observed in the whole layer of the gastric mucosa, which is termed automatic replication of immune cells. Abnormal proliferative transformation stage: presence of intranuclear milky globular body cells or signet-ring cell-like heterotypic cells at the junction of the gastric pit and the gastric gland, with proliferation of large numbers of immune cells and vacuolar degeneration of immune cells, which is termed the proliferation and degeneration of immune cells. Intraepithelial neoplasia stage: clonal hyperplasia of epithelial cells and immunosuppression. Conclusion For controlling the occurrence and development of gastric cancer and effective immune intervention, it is essential to grasp the relationship between H. pylori infection-induced changes in gastric mucosal immune cells and glandular epithelial cell damage and its histopathological characteristics.