Lymph node metastasis is the main and frequent metastatic way of lung cancer, it is also the reason of postoperative carcinoma residue which results in relapse and metastasis. It is vital to clean mediastinal lymph nodes and hilar lymph nodes in lung cancer operation. However, the patterns of lymphadenectomy are not yet uniform. There are complete mediastinal lymph node dissection(CMLND), radical lymph node dissection(RLND), lymph node sampling(LS), systematic lymph node sampling(SS) and sentinel lymph node navigation(SLN). And with the development of minimal invasive surgery, the thoracoscopic lymphadenectomy gets mature day by day. It is very necessary to find a more standardized and perfect patten of lymphadenectomy. This paper reviews the clinical significance, the pattens and the extent of mediastinal lymph node dissection and hilar lymph node dissection, and also reviews the current status and prospect of thoracoscopic lymphadenectomy