原发性肺癌是中国发病率和死亡率最高的恶性肿瘤，2015年中国肺癌新发病例约78.7万例，死亡病例约63.1万例。由于侵袭性高，且缺乏有效的早期发现手段，导致中国大部分肺癌患者就诊时已是Ⅳ期。化疗是治疗Ⅳ期肺癌的基石，但疗效不佳。近年来，随着分子靶向治疗、免疫治疗的飞速发展，Ⅳ期肺癌的治疗理念在不断发生变化，患者的生存也得到了很大改善。为了及时反映国内外Ⅳ期肺癌治疗的新进展，进一步提高中国Ⅳ期肺癌的规范化诊疗水平，中国医师协会肿瘤医师分会和中国医疗保健国际交流促进会肿瘤内科分会组织专家制定了《Ⅳ期原发性肺癌中国治疗指南(2021年版)》。“,”Primary lung cancer is the most common malignancy and the leading cause of cancer death in China, with an estimated 787 thousands incident cases and 631 thousands deaths in 2015. Due to its aggressive behavior and the absence of effective early screening methods, most patients with lung cancer in China are in stage Ⅳ when diagnosed. Chemotherapy is the cornerstone of stage Ⅳ lung cancer, but its efficacy is unsatisfactory. In recent years, with the rapid development of molecular targeted therapy and immunotherapy, the treatment concept has continuously changed and survival for patients has also been greatly improved. In order to update the progress in the treatment of stage Ⅳ lung cancer worldwide timely, and further improve the level of standardized diagnosis and treatment of stage Ⅳ lung cancer in China, Chinese Association for Clinical Oncologists and Medical Oncology Branch of Chinese International Exchange and Promotion Association for Medical and Healthcare organized experts to formulate “Clinical Practice Guideline for Stage Ⅳ Primary Lung Cancer in China(2021 version)” .