Common tumor markers for gastric cancer include CEA, or carcinoembryonic antigen, as well as CA19-9, CA125, and glycoantigens. In patients with gastric cancer, serological tests will show an increase in these tumor markers. In normal people, the tumor markers are low or negative. When a tumor is present, the increase of tumor markers in local tissues and body fluids is also an immune response of the body. Patients with gastric cancer may also exhibit significant epigastric pain, as well as acid reflux and belching after eating. The measurement of tumor markers can be used as a reference indicator of cancer, as well as a prediction of recurrence and metastasis after surgery. Patients with gastric cancer can be diagnosed early and choose surgery in time, and adjuvant treatment should be performed after surgery.