Chemotherapy for lung cancer can be divided into five categories according to the treatment method: radical chemotherapy, palliative chemotherapy, preoperative neoadjuvant chemotherapy, postoperative adjuvant chemotherapy, and thoracic and pericardial cavity chemotherapy. When choosing chemotherapy regimen for lung cancer in clinical practice, we must consider the following factors: 1. pathological type of lung cancer. 2. The physical status of the patient. 3. Pay attention to the patient’s past history and underlying diseases, such as patients with diabetes for paclitaxel that requires glucocorticoids to prevent allergy, should be evaluated for good glycemic control. 4, assess the patient’s tolerance of chemotherapy side effects, for example, patients who cannot have central venous cannulation, the use of vincristine will have some difficulties. 5.Family economic situation. In addition, the alteration of some molecules on tumor cells may make chemotherapy drugs less effective in killing tumor cells. For example, it was found that the alteration of some genes makes the detoxification of a certain drug affected, which makes its side effects increase significantly. Once the research data are further matured, we should also obtain as much information as possible on the detection of the above molecular markers when choosing chemotherapy regimens, and develop individualized regimens for each patient when choosing chemotherapy regimens to improve chemotherapeutic efficacy and minimize toxicity. Moreover, not all lung cancer patients are suitable for chemotherapy. Contraindications to chemotherapy include the following common aspects: 1. Patients with KPS<60 or ECOG>2 should not be treated with chemotherapy. 2. Lung cancer patients with white blood cells less than 3.0×10^9/L, platelets less than 60×10^9/L and red blood cells less than 2×10^12/L should not undergo chemotherapy. 3. Lung cancer patients with serious heart, liver and kidney dysfunction or serious complications and fever of infection and bleeding tendency should not undergo chemotherapy. 4. In chemotherapy, if the following conditions occur, drug reduction, discontinuation or drug change should be considered: the lesion still progresses after 2 cycles of treatment, or deteriorates again during the rest period of chemotherapy cycle; when the adverse reaction of chemotherapy reaches grade 4, which is obviously threatening to the patient’s life; when serious complications occur. Chemotherapy can all lead to anorexia, nausea, vomiting, diarrhea and other gastrointestinal reactions, resulting in nutritional loss and inadequate supplementation. When patients have malnutrition, they should be given supportive treatment promptly and early, and appropriate modalities should be selected according to the patient’s condition: oral, enteral and parenteral nutrition. A reasonable diet is very important. It is important to consume sufficient calories and proteins, eat vitamin-rich vegetables and fruits, avoid taking stimulating foods as much as possible, and eat less and more meals.