Helicobacter pylori (Hp) was first identified and isolated in 1982, and the discoverers, Warren and Marshall, were awarded the Nobel Prize in Medicine and Physiology in 2005. The most important clinical treatment is the treatment of peptic ulcer, while the role of Hp is also extremely important in the common clinical chronic gastritis. Hp infection can lead to three different types of chronic gastritis: superficial gastritis, diffuse sinusitis, and multifocal atrophic gastritis. chronic gastritis due to Hp infection begins in the gastric sinus and gradually extends to the entire stomach along the lesser curvature. The degree of chronic inflammatory cell infiltration is closely related to the number of infected Hp, but is reduced when the gastric mucosa is accompanied by severe glandular atrophy or intestinal epithelial hyperplasia. In the Correa model, persistent chronic gastritis due to Hp infection can progress gradually leading to glandular atrophy and intestinal epithelial hyperplasia. The incidence and severity of gastric mucosal atrophy increases with the duration of Hp infection, and the atrophy is most likely the result of bacterial action or of a chronic inflammatory response. The two main objectives of treatment of Hp-associated gastritis are: first, eradication of Hp may relieve dyspeptic symptoms in patients with chronic gastritis; second, it may prevent further progression to atrophy, intestinal epithelial hyperplasia, atypical hyperplasia and even gastric cancer. However, it is still uncertain whether intestinal epithelial hyperplasia and gastric mucosal atrophy can be reversed after Hp eradication, and most studies have not confirmed that atrophy and intestinal epithelial hyperplasia can be improved after Hp eradication and active inflammation of the stomach subsides, but may delay their progression to precancerous lesions and even gastric cancer. Infection is the most common cause of chronic gastritis, and the outcome after infection depends heavily on factors such as the strain itself and the genetic background of the host.