Gastroscopy with tissue biopsy is an important tool for early detection of gastric cancer. Gastroscopy should be performed in a timely manner in the following cases, and some patients even need long-term and regular follow-up gastroscopy: 1. symptoms such as upper abdominal fullness, acid reflux, burping and belching for a long time; 2. poor appetite, loss of appetite, weakness and weight loss; 3. nausea or even vomiting; 4. difficulty in swallowing; 5. black stool or tarry stool, vomiting blood; 6. Unexplained anemia; 7. History of gastritis or gastric ulcer and recent aggravation of upper abdominal pain or discomfort; 8. History of ulcer over 40 years of age; 9. Family history over 40 years of age; 10. Regular review after gastric surgery; 11. Other conditions that need to exclude gastric diseases. In recent years, gastric cancer has a tendency to become younger, so attention should be paid to learning to relieve work and study pressure, eating and sleeping regularly, and seeking medical consultation in time when discomfort occurs. At the same time, we should pay attention to taking tissue biopsy from suspicious areas at multiple points during gastroscopy, and should not blindly judge it as gastritis or gastric ulcer without taking tissue biopsy to avoid delaying the diagnosis.