Deproteinized bovine bone mineral has been widely used as graft material in sinus augmentation procedure. The efficacy of OCS-B(r)(Nibec Inc., Seoul, Korea) as a graft material for sinus augmentaion was evaluated in 10 patients. A total of 13 sinus augmentation procedures were performed, and an average of 6.3 months later 27 implants were placed into the augmentation sinuses. The biopsy specimens were examined histologically and hitomorphometrically. Radiographical evaluation was done also. The average distance form grafted sinus to implant apex at the final evaluation period was $5.7pm3.1$mm. The average percentage of newly formed bone at an average of 6.3 months was $20.0pm8.4%$. The degree of bone to graft material contact was $18.7pm6.4%$. It was shown from both radiographic evaluation and histologic results that sinus augmentation can successfully be performed with <TEX>$OCS-B^textcircledR$<TEX>.