Helicobacter pylori (H. pylori) is a Gram-negative bacterium that is curved in an anti-S or arc shape and is mainly parasitic on the mucosa near the pylorus and sinus of the stomach. It is one of the most famous bacteria in the world, why? Because one of the two scientists who discovered it, Professor Marshall, “tested the bacteria” by swallowing H. pylori and got gastritis as expected, thus confirming that H. pylori causes gastritis. Two Australian scientists, Barry J. Marshall and J. Robin Warren, were awarded the 2015 Nobel Prize in Physiology and Medicine for their “discovery of H. pylori and the role of this bacterium in They were awarded the 2015 Nobel Prize in Physiology and Medicine for “the discovery of H. pylori and the role it plays in diseases such as gastritis and ulcers. H. pylori is responsible for many digestive disorders, such as about 70 percent of indigestion, acute and chronic gastritis, peptic ulcers, gastric MALT lymphoma and gastric cancer. It can cause gastric cancer, but in the age of “cancer talk”, there is no need to panic because the infection rate of H. pylori in China is about 50%, but less than 1% of infected people will develop gastric cancer. The 2014 Kyoto International Consensus defines H. pylori infection as an infectious disease. All H. pylori infected individuals are treated for eradication. The fifth H. pylori consensus issued in China in 2016 states that Hp infection is the most important controllable risk factor for preventing gastric cancer and eradication of Hp should be a primary preventive measure for gastric cancer. However, the high prevalence of infection in China makes active screening and treatment of the entire population unrealistic, so eradication indications suitable for our population have been developed (see Table 1) It should be noted that China is a country with a high incidence of gastric cancer, and the high-risk population for gastric cancer cannot only perform H. pylori testing, but also requires gastroscopic screening for comprehensive assessment. High-risk groups for gastric cancer 1.Age ≥ 40 years old, male or female; 2.People in areas with high incidence of gastric cancer; 3.People with Hp infection; 4.Pre-cancerous diseases of the stomach such as chronic atrophic gastritis, gastric ulcer, gastric polyp, post-surgical residual stomach, hypertrophic gastritis, pernicious anemia, etc.; 5.First-degree relatives of gastric cancer patients; 6.The presence of other risk factors for gastric cancer (such as intake of high salt, pickled diet, smoking, heavy alcohol consumption, etc.)