Chemotherapy is usually available 3-4 weeks after lung cancer surgery. Whether chemotherapy is needed after lung cancer surgery depends on the postoperative pathological stage. If it is early stage of lung cancer, no chemotherapy can be done after surgery; if it is stage Ib or above of lung cancer, chemotherapy is often needed after surgery, which is usually done in 3-4 weeks. However, the specific time should be based on the condition, if the patient recovers faster after surgery and is in better physical condition, he/she can also have chemotherapy earlier, on the contrary, he/she needs to postpone chemotherapy; the purpose of postoperative chemotherapy is to prevent recurrence and metastasis after surgery. Pay attention to the side effects of chemotherapy; patients may have gastrointestinal reactions such as vomiting and nausea, loss of appetite, etc. Others may have the side effects of hair loss and decrease of blood cells. Lung cancer patients should undergo chemotherapy under the guidance of physician’s consultation after surgery, and if side effects occur during chemotherapy, they should reflect the situation to the attending physician in time, and patients should not use drugs on their own to avoid adverse consequences.