Not all patients are suitable for chemotherapy and some have contraindications: 1. Systemic failure or malignant disease, such as functional status score (Kamofsky score) assessment of 60 or less generally should not use systemic chemotherapy. 2. Anthraquinone antibiotic chemotherapeutic agents, especially adriamycin, are contraindicated in cardiac failure, and high doses of cyclophosphamide and fluorouracil, triclosan and camptothecin can also cause cardiotoxicity. 3. Systemic chemotherapy should not be used when there is obvious jaundice or liver function abnormality, and should not be used again if liver function abnormality occurs repeatedly after chemotherapy. 4. Cisplatin and high-dose methotrexate are prohibited in renal insufficiency, and even if the renal decompensation is only mild in elderly patients, the dose of cisplatin should be reduced, and it is even more forbidden to use the drug in large doses at one time. 5. Bleomycin, methotrexate and leucovorin are prohibited in severe pulmonary decompensation. 6. Systemic chemotherapy (except cisplatin and adrenocorticotropic hormone) is generally contraindicated in patients with obvious bone marrow insufficiency, such as absolute peripheral blood granulocyte count is less than 1.5×10⁹/L or platelet count is less than 50×10⁹/L, when chemotherapy is used with caution. 7. Systemic chemotherapy should not be used for those with fever, hemorrhage, infection, large amount of ascites, water loss, electrolyte and acid-base balance imbalance. 8. Chemotherapy should not be used within 2 weeks after gastrointestinal anastomosis (except for endoluminal chemotherapy). 9. After the end of extensive radiotherapy, it is necessary to rest for 2 to 4 weeks before using systemic chemotherapy. 10. Those who are known to be allergic to certain types of chemotherapeutic agents. Although tumor patients can prolong survival, reduce postoperative recurrence and metastasis, and improve the quality of life of tumor patients through chemotherapy, whether the patients are suitable for chemotherapy or not requires physicians to give appropriate treatment plan according to the patient’s condition.