There is no best chemotherapeutic drug, only the most suitable drug for the patient. Commonly used chemotherapeutic drugs include alkylating agents, antimetabolites, plant bases and other natural products, antitumor antibiotics and other classes of chemotherapeutic drugs, the choice of drugs is analyzed according to the disease and patient’s tolerance, and the drugs should be used in accordance with the doctor’s prescription. 1. Alkylating agents: nitrogen mustards such as cyclophosphamide and nitrogen mustard can treat lymphoma and multiple myeloma, etc.; vinyl imines such as tiotropium can treat ovarian cancer and breast cancer, etc.; nitrosoureas such as carmustine and nimustine can treat primary tumors of the skull and brain or intracranial metastases. 2. Anti-metabolites: folic acid analogs can treat acute lymphoblastic leukemia, breast cancer, etc. Purine analogs are mainly used to treat hematological malignant tumors, and pyrimidine analogs are often used to treat gastric cancer, colorectal cancer, and acute leukemia. 3. Plant bases and other natural products: vincristine can treat leukemia and bladder cancer, etc., oncotoxin can treat testicular cancer and acute leukemia, etc., paclitaxel can be used for malignant tumors of ovary and breast, and camptothecin can treat ovarian cancer and small-cell lung cancer. 4. Anti-tumor antibiotics: actinomycin D can treat neuroblastoma, anthracycline antibiotics can treat leukemia and lymphoma, etc. Other antibiotics such as bleomycin can treat testicular cancer. 5. Others: platinum drugs such as cisplatin and carboplatin can treat breast cancer; methylhydrazine can treat malignant lymphoma. Those who need chemotherapy need to consult the doctor in time and receive standardized treatment.