Objective To study the method of treating hemifacial atrophy withfree serratus muscle flap. Methods Three patients diagnosed as having serious hemifacial atroph was treated with free serratus muscle flap. The root of the flap was thoracodorsal artery and thoracodorsal vein, which was anastomosed with superficial temporal artery and vein, facial artery and vein, lingual artery and vein,and so on.During the operation, long thoracic nerve was dissected and anastomosed with facial nerve. The sizes of the flaps were 12 cm×8 cm16 cm×12 cm.Results All free-muscle flaps healed well after the transplant. The face and buccal area looked chubby and rounded. There were no obvious protuberance and discontentment on the buccal area. The shoulders of all patients moved well. The facial contourof the patients recovered well during the follow-up period (1.3 years). Conclusion The method has a good result, The long-term effect needs further study.