The establishment of laboratory animal models persistently infected with Helicobacter pylori (H. pylori) has been difficult, but strongly required to document the causative role of H. pylori on ensuing gastritis, peptic ulcer disease and even gastric cancer. Although H. pylori are generally regarded as the most important etiologic agent of chronic active gastritis, peptic ulcer diseases, primary gastric marginal zone lymphoma, and gastric cancer, the detailed pathogenic mechanisms are not resolved. In an effort to develop an animal model that could show the same course of the infection that occurs in the human host, diverse kinds of animal model have been proposed. This review attempted to highlight salient features of H. pylori-infected animal models. (Korean J Gastroenterol 2001;37: 399-405)