Objectives: This study evaluated implant success rate, survival rate, marginal bone resorption of implants, and material resorption of sinus bone graft in cases wherein tapered body implants were installed. Materials and Methods: From September 2003 to January 2006, 20 patients from Seoul National University Bundong Hospital, with a mean age of 54.7 years, were considered. The mean follow-up period was 19 months. This study covered 50 implants; 14 implants were placed in the maxillary premolar area, and 36 in the maxillary molar area; 24 sinuses were included. Results: The success rate was 92%, and the survival rate was 96.0%. The mean amount of sinus augmentation was $12.35{pm}3.27$ mm. The bone graft resorption rate one year after surgery was $0.97{pm}0.84$ mm; that for the immediate implantation group was $0.91{pm}0.86$ mm, and that for the delayed implantation group was $1.16{pm}0.77$ mm. However, the difference was not statistically significant. The mean marginal bone resorption one year after restoration was $0.17{pm}0.27$ mm (immediate group: $0.12{pm}0.23$ mm; delayed group $0.40{pm}0.33$ mm); statistically significant difference was observed between the two groups. Conclusion: Tapered body implant can be available in the maxillary posterior edentulous ridge which sinus bone graft is necessary.