Objective:To study the application of serratus anterior muscle flap transplantation in expander-based implant breast reconstruction and its clinical significance. Methods:Forty-seven breast cancer patients received modified radical mastectomy or mammectomy (a total of 47 breast) were enrolled. They have taken staging breast reconstructoin using soft tissue expanders (SRTX). Then the clincal results have been observed,recorded and analyzed. The serratus anterior muscle flap was used as lateral coverage in the operation. The complications such as postoperative capsular contracture,seroma,hematoma,incision dehiscence and infection have been recorded in both periodⅠ and periodⅡ operations. Results:Of all patients (47 cases),there was no complication such as hematoma,infection,or skin flap necrosis happened during the follow up after periodⅠ and periodⅡ operations. Only 2 cases (2 sides) had incision dehiscence after periodⅠ. During the follow-up period(465.0 ± 2.5) days,no capsular contracture happened. Conclusion:Using anterior serratus muscle flap in expander-based implant breast reconstruction can fix the expander and implant,reduce complications,prevent breast implant displacement and create good breast shape.