Colostrum basic proteins (CBP) (MW 1$sim$30 kDa) were isolated from bovine colostrum using a series of ultrafiltration processes and their effects on osteoblast cell proliferation and bone metabolism were investigated in cell line and animal models. Treatments with CBP (1, 10, 100 $mu$g/mL) dose-dependently increased cell proliferation of osteoblastic MC3T3 cells. Alkaline phosphatase activity, a marker of osteoblastic phenotype, in the cells was also increased after treatments with CBP in a dose-dependent manner. Significant increases in bone density were observed in femur of ovariectomized rats which were fed a diet with 1% and 10% CBP, compared to rats fed a normal diet. These results suggest that CBP may increase bone mass and density and be useful for the prevention of bone-related diseases.  장 소 : 농업기반공사 교육원(전산실) ※ 자세한 사항은 (사)한국지하수토양환경학회 홈페이지 ( http://www.kossge.or.kr ) 을 참조하십시오.??                               ??