Gastric cancer is a malignant tumor originating from the epithelium of gastric mucosa, which is one of the major diseases endangering people’s health in China. China is a country with high incidence of gastric cancer, with about 400,000 new cases of gastric cancer and 350,000 deaths each year, accounting for 40% of the new cases and deaths in the world. Even if the progressive gastric cancer receives comprehensive treatment mainly by surgery, the 5-year survival rate is still less than 30%, and the quality of life is low, which brings heavy burden to families and the country, while most early gastric cancers can be treated radically under endoscopy, and the 5-year survival rate is more than 90%. As most of the early gastric cancers can be treated radically under endoscopy and the 5-year survival rate is more than 90%, screening and early diagnosis and treatment by endoscopy in the high-risk group of gastric cancer is a feasible way to diagnose and treat the serious form of gastric cancer in China. According to the national situation and the epidemiology of gastric cancer in China, those who meet any of the following criteria 1 and 2-6 should be listed as the high-risk group of gastric cancer and recommended as the target of screening: 1.Age 40 years old or above, male or female; 2.People in areas with high incidence of gastric cancer; 3.People with H. pylori infection; 4.Patients with chronic atrophic gastritis, gastric ulcer, gastric polyp, post-surgical residual stomach, hypertrophic gastritis, pernicious anemia and other gastric cancer Pre-cancerous diseases; 5. First-degree relatives of gastric cancer patients; 6. Other high-risk factors for gastric cancer (high salt, pickled food, smoking, heavy alcohol consumption, etc.).