Abstract: Lung cancer is the leading cause of cancer-related death of high morbidity and mortality with poor prognosis. Efficacy of chemotherapy and molecular targeted therapy had reached the plateau. The immunotherapies, especially the checkpoint inhibitors, offer a novel approach for the treatment of patients with non-small cell lung cancer (NSCLC) because of its high response rate, less adverse reactions and well tolerance. The purpose of this paper will draw a summary on the theory, effect, toxicity and problems to be solved of the checkpoint inhibitors therapy in NSCLC.