Currently, the main markers of gastric cancer used in clinical practice are CEA and CA19-9, but none of them has strong specificity; combined testing can increase its sensitivity and specificity. (1) CEA: carcinoembryonic antigen, a polysaccharide-rich protein complex, is a carcinoembryonic antigen produced in embryonic and fetal stages, which is significant to the prognosis of gastric cancer, and is related to progressive hypofractionated adenocarcinoma, as well as tumor size, plasma surface infiltration and lymph node metastasis. If the CEA level decreases by more than 50% or to normal range and lasts for more than 4 weeks, it can be used as an effective indicator of treatment; if it continues to increase after treatment, it indicates poor prognosis. (2) CA19-9: It is a kind of large mucus-containing glycoprotein, which is related to tumor size, lymph node metastasis and depth of infiltration, and is an independent indicator to determine the prognosis of gastric cancer patients. High level of CA19-9 in serum indicates shortened survival of gastric cancer patients, and can be used in combination with other indicators to indicate peritoneal recurrence and abdominal implantation of gastric cancer, which is a more sensitive indicator than CEA.