Neoadjuvant chemotherapy, i.e., chemotherapy given after the tumor is clearly diagnosed, i.e., preoperative chemotherapy. The advantages of neoadjuvant chemotherapy include: 1. eliminating micro metastases; 2. potentially preventing the formation of drug-resistant cell lines; 3. shrinking the tumor and facilitating surgery; 4. the clinical and pathological response after chemotherapy can be used to judge the prognosis and provide a basis for further selection of appropriate treatment; 5. reducing the viability of tumor cells and decreasing the chance of distant dissemination. Free cancer cells are often found in the blood flow of gastric cancer patients, and surgery can easily cause metastasis and implantation of cancer cells; therefore, pre-surgical chemotherapy can both kill micro-metastases outside the surgical area and prevent possible dissemination due to surgery. In addition, preoperative chemotherapy can shrink the primary foci and reduce the adhesions between tumor and surrounding tissues, which is conducive to the radical surgery and narrowing the resection area and preserving the surrounding tissues and organs. Through preoperative chemotherapy, the in vivo drug sensitivity information of tumor can be obtained, which can provide the basis for the selection of postoperative adjuvant chemotherapy regimen. Currently, neoadjuvant chemotherapy with captanabine and oxaliplatin is used for gastric cancer, especially for patients with intermediate and advanced stages. Neoadjuvant chemotherapy has a very good application prospect in the treatment of gastric cancer.