Although the incidence and mortality rates of gastric cancer in China have decreased in recent years, the population base in China is large and the combined number of new cases and deaths is about 1 million each year, and its survival rate is lower than that of other cancers, which seriously threatens the health and safety of the nation. The occurrence of gastric cancer is a complex multi-factorial and multi-step evolutionary process. The factors include H. pylori infection, genetic factors, environmental factors, and human factors. The incidence of H. pylori infection is usually more than 6 times higher than that of the general population, and the International Agency for Research on Cancer (IARC) under the World Health Organization has classified H. pylori infection as the first group of carcinogens for human gastric cancer. H. pylori infection causes superficial gastritis, but only some patients progress to precancerous lesions such as atrophic gastritis and intestinal metaplasia, leading to intestinal gastric cancer in about 1% of patients. Although only about 1% of HP-infected patients will develop gastric cancer, the large number base in China, coupled with the high rate of H. pylori infection, means that to prevent gastric cancer, we can prioritize the eradication of symptomatic H. pylori-infected patients; and we need to complete eradication treatment before gastric mucosal atrophy or intestinal metaplasia, so that patients with intestinal metaplasia will not be able to reverse it when eradicating H. pylori (i.e., it cannot be reversed to atrophic gastritis, non-atrophic gastritis, the gastric mucosa, etc.). Although H. pylori is an important initiator of precancerous lesions, it is not the only factor that causes gastric cancer. Genetic and environmental factors are unavoidable, and it is difficult to avoid them. However, the “human factors” are in our hands. 1.Change bad habits, try to stay up less, exercise more and improve our immunity; 2.Create good eating habits, less meat, less salt, less wine, less smoking, stay away from pickled and smoked products and leftovers, eat more fresh vegetables and fruits, try to have “fresh food at all times, clear meals”. 3, regular physical examination, enhance health care awareness. Especially for people over 40 years old, the annual physical examination should increase the “gastroscopy” one.