The purpose of this study was to evaluate the effects of DFPR on differentiation of mouse calvarial cell in vitro, to examine the possibility for periodontal regeneration. $10{mu}g/ml$ of DFPR was used as experimental concentration. osteogenic medium only was assigned as control, Experimental 1 was supplemented with 10nM dexamethasone, Experimental 2 with $10{mu}g/ml$ DFPR and Experimental 3 with l0nM dexamethasone + $10{mu}g/ml$ DFPR. cellular activity was evaluated by MTT method at 8, 12, 16 days, expression of mRNA of ALP, osteopontin, osteocalcin, collagen type-l was detected by RT-PCR method at 4, 8, 12, 16 days of culture. extent of mineralization was observed by Von Kossa staining at 16 day of culture. The results are as follows 1)Any acceleration of differentiation was not observed at expression of differentiation marker, 2) Decrease in expression of extracelluar matrix and in bone nodule formation was observed The results suggested that DFPR have negative effect on the rate of differentiation on rat calvarial cell, decrease extracelluar matrix formation ,decrease bone nodule formation. Ongoing studies are necessary in order to determine effect of DFPR on periodontal regeneration.