Whether chemotherapy is needed after gastric cancer surgery depends on the stage of gastric cancer, as follows: 1. Early gastric cancer: early gastric cancer without lymph node metastasis can be considered for endoscopic treatment or surgery according to the depth of invasion, and adjuvant chemotherapy is not needed after surgery. Both early gastric cancer and locally progressive gastric cancer should be treated with the aim of cure, and complete removal of primary foci of gastric cancer, metastatic lymph nodes and infiltrated tissues is the basic requirement of radical surgery for gastric cancer, and also the main means to achieve the goal of cure at present. At present, it is believed that even if patients with early gastric cancer do not receive adjuvant chemotherapy, the five-year survival rate after surgery can reach about 95%, so adjuvant chemotherapy after surgery is not recommended. 2. Middle and late gastric cancer: middle and late gastric cancer is difficult to be removed by surgery due to the large extent of tumor invasion, or the surgery is more damaging to the patient’s body. Chemotherapy is needed after surgery to eliminate tiny residual lesions, reduce the risk of recurrence and metastasis, and improve the cure rate. Therefore, whether chemotherapy is needed after gastric cancer surgery depends on the specific stage of gastric cancer and the patient’s physical condition.