How long chemotherapy for advanced lung cancer generally takes needs to be decided according to the sensitivity of patients to chemotherapy. If the patient is more sensitive to chemotherapy, and the efficacy is judged to be complete remission clinically after the patient receives six cycles, that is to say, the tumor lesions cannot be seen by the naked eye, the patient can be taken for clinical observation or maintained with a single drug from previous treatment, that is to say, chemotherapy needs about 5.5-6 months, or maintained with a single drug, and the duration of the treatment cannot be decided. If the patient is not sensitive to chemotherapy, and the efficacy is judged to be progressive after receiving two cycles of a program, it is necessary to change the chemotherapy program to treat, and how long the treatment in such a case will depend on the specific situation.