In order to facilitate the understanding of lymphatic drainage of lung cancer and the accurate recording of surgery as well as the proximity and distance of the cancer foci, the lymph nodes in the chest cavity of lung cancer were divided and lymph nodes were delineated. 9 lymph nodes of the inferior pulmonary ligament 10 lymph nodes of the hilar (main bronchus) 11 interlobular lymph nodes 12 lobe (upper, middle and lower lobe) bronchial lymph nodes 13 segmental bronchial lymph nodes 14 distal bronchial lymph nodes below the segmental level lymph node delineation lymph node delineation refers to the lymph nodes closer to the primary focus as line 1, followed by line 2, line 3 and even line 4. line 1 includes lymph nodes of zones 12, 13 and 14 line 2 In general, with a right-sided chest opening, the upper mediastinal lymph nodes, the inferior ramus lymph nodes and the inferior mediastinal lymph nodes can be thoroughly explored and dissected. In left-sided open chest, the upper mediastinal lymph nodes are difficult to access due to the obstruction of the aortic arch, so a sample biopsy can be performed without routine clearance. The areas that can be cleared are mainly the para-aortic and subaortic lymph nodes, the inferior ramus lymph nodes, and the inferior mediastinal lymph nodes.