Abstract: Objective To explore the method of implant coverage with pectoralis major fascia in immediate implant-based breast  reconstruction  and  to evaluate the feasibility and security.Methods 27 patients with early breast cancer underwent immediate implant-based breast reconstruction after mastectomy with the implant covered by a musculofascial layer composed of the pectoralis major muscle and the superficial pectoral fascia.The therapeutic efficiency and safety was evaluated by retrospectively analyzing the clinical data including the short-and long-term complications，cosmetic results，local recurrence，distant metastases and mortality rates.Results Minor and major complications were reported in a period of follow-up ranging from 3～28 months（median，13 months）.One patient had partial nipple necrosis postoperatively and was cured，and no other postoperative complications of hematoma，infection was found.During the follow-up period，no exposure of the implant，implant displacement and capsular contracture were observed.The reconstructive outcomes were excellent in 21 cases and good in 6 case，with an excellent and good rate of 100%.No local recurrence or distant metastasis or death occurred in any of the patients.Conclusion The superficial pectoral fascia flaps can be effectively and safely used as an autologous tissue layer to cover implant in immediate breast reconstruction after mastectomy.

Key words: breast neoplasms, mastectomy, immediate reconstruction, implant, fascia