Objective:To explore the obliteration of the old mastoid cavity and reconstruction of the posterior canal wall after radical mastoidectomy. Method:Posterior canal wall reconstruction and mastoid obliteration of 11 ears of 10 patients with old mastoid cavity for 1 to 6 years after radical mastoidectomy were done using the pedicle postauricular composite skin flap (PPCSF),and their tympanoplasty were performed at the same time. Follow-up was performed at 3 to 30 months. Result:All PPCSFs survived. The old mastoid cavity of 11 ears vanished and reconstructed posterior canal wall remained in normal position without retraction. The drying ear time took 2 to 3 weeks postoperatively,and the symptoms of the radical cavity disease after radical mastoidectomy were cleared up nearly,and the average hearing threshold decreased 13.6 dB HL. The otorrhea and perforation of tympanic membrane resulted from infection happened to 1 of 11 ears three month after the operation. Conclusion: The PPCSF is an effective method in the obliteration of old mastoid cavity and reconstruction of the posterior canal wall. It can reduce drying ear time postoperatively, treat the radical cavity disease after radical mastoidectomy and is beneficial to the tympanoplasty at the posterior external at the same time.