Missing of the upper posterior dentition can cause alvolar bone resorption & pneumatization of Maxillary sinus wall, which makes traditional implant placement impossible. The solution includes various methods to the posterior maxilla to provide adequate bone support for implant installation and long-term survival.--sinus floor elevation, sinus-lift graft using Lefort I osteotomy, onlay graft. This is a clinical & retrospective study on implant surgery & prosthodontic restoration with upper edentulous posterior jaw from Jan. 1990. to Jun 1997 at implant clinic of Chonbuk National University Hospital. The results obtained were as follows : 1. Six hundred ninety-nine implants were placed on upper posterior jaw of two hundred seventeen patients among them one hundred sixty-five implants were placed in forty-four patients with sinus lift. 2. The height of the remained alveolar bone was classified on the base of Misch's concept. This included seventynine SA-ls, ninety-seven were successfully ninety-seven SA-2s, sixty-five SA-3s and sixty SA-4s. 3. Ninety percent of implants were successfully integrated in non0grafted area and eighty- seven percent of implants were successully integrated in sinus lift area.