Objective：To evaluate the therapeutic effect and surgical technique of mastoscopic axillary lymph node dissection (MALND). Methods：The clinical data of 100 patients with breast cancer undergoing mastoscopic (50 cases) or conventional (50 cases) axillary lymph node dissection since Dec. 2008 were retrospectively analysed. The parameters including the operating time, bleeding volume, number of lymph nodes removed, lymph node metastasis, hospital stay and occurrence of postoperative complication were compared respectively between the two groups. Results：No differences were noted in the average number of lymph node harvested, lymph node metastasis and hospital stay between the two groups (P＞0.05). Although the mastoscopic procedure showed longer operating duration than conventional procedure［(221.85±19.61) min vs. (140.05±13.95) min］ (P=0.000), it had less bleeding (P=0.012) and lower postoperative complication rate (P=0.034) than that of conventional surgery. Conclusions：MALND is worth being promoted for broad clinical applications owing to its advantages of minimal invasion, simple procedure, low complication rate, rapid recovery and invisible scar. However, the surgical technique of MALND remains to be further improved to reduce the prolonged operating time.