The purpose of this study was to investigate the effects of irradiated frozen allogenic bone(IFAB) on the cell proliferation and differentiation of human fetal osteoblasts. Human fetal osteoblasts(hFOB1) were cultured to examine the cellular proliferation for 3 days and 5 days with $1mg/m{ell}$, $100{mu}g/m{ell}$, $10{mu}g/m{ell}$, $1{mu}g/m{ell}$, $100ng/m{ell}$, $10ng/m{ell}$, $1ng/m{ell}$ of IFAB, and to compare the ALP synthesis to control groups for 3 days with DMEM/F-12 1:1 Mixture and $1mg/m{ell}$, $100{mu}g/m{ell}$, $10{mu}g/m{ell}$, $1{mu}g/m{ell}$, $100ng/m{ell}$, $10ng/m{ell}$, $1ng/m{ell}$ of IFAB. To compare the calcium accumulation, hFOBl cultured for 23 days were quantified and photographed. The cellular proliferation of hFOBls treated with IFAB was increased at 5 days to control(p<0.05). The activity of ALP in hFOBls treated with $100ng/m{ell}$ IFAB was significantly increased at 5 days(p<0.05). A quantified calcium accumulation in hFOBl was significantly increased at $100ng/m{ell}$, $10ng/m{ell}$ of IFAB(p<0.05). In the present study, we found that IFAB playa important role of bone formation in the early stage. There was considered that IFAB could be used in the bone graft material.