The implant prosthesis has been extensively used in clinic recently, and implant failure is appearing. Many factors may cause the failure, and they work together generally. This paper summarizes and analyzes the failure cases related to implant treatment and relevant risk factors of oral implants in Department of Implantation, School of Stomatology, The Fourth Military Medical University during the past six years, in order to improve the success rate of implant prosthesis and provide guidance for clinical application.