The more sensitive chemotherapeutic indexes of stomach cancer include CA72-4, CEA (carcinoembryonic antigen) and CA19-9, etc. However, they are only used as auxiliary means, and the diagnosis of stomach cancer requires multiple examinations, such as gastroscopy and pathology examination. Tumor markers, mainly CA72-4, CEA (carcinoembryonic antigen) and CA19-9, which are more sensitive indicators of gastric cancer, can be significantly elevated in the early stage of gastric cancer. In addition, CA125 for peritoneal metastasis and AFP for special pathological types of gastric cancer have certain diagnostic and prognostic value. However, tumor markers are only used as an auxiliary diagnosis of gastric cancer, and gastroscopy and pathological examination of diseased tissues are required for a definite diagnosis, which is the gold standard of gastric cancer diagnosis. It is recommended that patients should choose appropriate methods under the guidance of doctors and take active treatment after the cause is clarified, so as to avoid delaying the condition.