Early symptoms of gastric ulcer cancer are called “alarm symptoms” in medicine, which include increased pain, weight loss, vomiting blood or black stools, anemia. Gastric cancer has a high-risk group, and the high-risk group has the following characteristics: long-term smoking; preferring smoked, high-salt pickled and fried food; aged over 40, especially the elderly over 60; having gastric cancer patients in the family; having pre-cancerous gastric diseases, such as gastric ulcers, atrophic gastritis, gastric polyps, Barrett’s esophagus and so on; and pathological biopsy of atypical proliferation, and so on. To prevent gastric ulcer from becoming cancerous, early screening should be done, and early screening includes: i. tumor marker test, such as blood sampling for carcinoembryonic antigen, CA19-9, etc.. Second, serum gastric function test, such as serum pepsinogen, serum gastrin determination. Gastroscopy. Helicobacter pylori test.