Etiology: The etiology is not known and may be related to the following factors Benign chronic diseases of the stomach: such as gastric ulcer, gastric polyp, atrophic gastritis, post-gastrectomy remnant stomach, etc. Heterotypic hyperplasia of the gastric mucosal epithelium. Helicobacter pylori, environmental and dietary factors: conversion of smoked and salted food into nitrate in the stomach is related to the occurrence of gastric cancer. Clinical symptoms: Stomach cancer is often asymptomatic in the early stage, and more obvious symptoms appear only when tumor development affects the function of stomach. Stomach pain: It is the most common symptom and the most non-specific and easy to be ignored. Nausea, vomiting, loss of appetite, emaciation, weakness, stomach bleeding and black stool. Auxiliary examinations: barium X-ray, gastroscopy, ultrasonography, biochemical and immunological tests for gastric cancer, etc. Treatment: Surgery is the main means to treat gastric cancer and the only way to cure it at present. Treatment plan should be formulated according to the strict staging and individualized principles of gastric cancer, and early surgical treatment should be pursued. For middle and late stage gastric cancer, comprehensive treatment including preoperative and postoperative chemotherapy, radiotherapy and immunotherapy can improve the curative effect. Suggestion: Generally, the treatment plan should be decided by a specialist after consultation and treatment according to the actual situation of the patient.