Abstract: Lung cancer is the most common malignancy in humans, and its morbidity and mortality have been increasing in recent years. In fact, the therapeutic effect of lung cancer treatment has not been significantly improved. The 5- year survival rate is just 10%~15%. Metastasis is one of the major factors affecting the prognosis of patients with lung cancer. Lymph node metastasis is the major route for metastasis of lung cancer, so immune status of the sentinel lymph node may be a chief factor in metastasis of lung cancer. Further studies on the sentinel lymph node of lung cancer are to be expected. The following is the summary of the study.