Lung cancer is one of the malignant tumors with the highest incidence and mortality rate, and everyone is afraid of it. There are many causes of lung cancer: long-term heavy smoking, ionizing radiation, occupational and environmental exposures, atmospheric pollution, previous chronic lung infections, genetics, etc. In China, there are more than 730,000 new lung cancer patients each year, and about 30%-40% of non-small cell lung cancer patients in China have EGFR mutations. Among patients with EGFR mutations who have received EGFR-TKI drugs (e.g., gefitinib, erlotinib, erlotinib), about two-thirds of them will develop drug resistance due to T790M mutations, leading to disease progression again. Patients are in urgent need of new treatment options. Recently, the State Food and Drug Administration announced good news: they officially approved AstraZeneca’s third-generation targeted lung cancer drug Teresic (i.e., oseltinib mesylate tablets) for clinical treatment. Ocitinib, an oral, irreversible agent-selective EGFR mutation inhibitor, is the first oncology drug marketed worldwide and the first approved in China for EGFR T790M mutation-positive locally advanced or metastatic non-small cell lung cancer. Its approval brings new hope to Chinese lung cancer patients with high prevalence of EGFR mutation. Ocitinib breaks the bottleneck of Chinese lung cancer patients who have no drug to treat after resistance to EGFR-TKI therapy, and is a major progress in targeted lung cancer therapy, which will allow more lung cancer patients to continue to achieve high quality survival in the future