Recently, many natural medicines, whose advantages are less side effects and possibility of long-term use, have been studied for their capacity, their anti-bacterial and anti-inflammatory effects and regenerative potential of periodontal tissues. Cervi Parvum Cornu(CPC) have been traditionally used as an hale, growth, hematogenous, anti-aging, back pain in Eastern medicine. The purpose of present study was to investigate the effects of CPC extract on cell cycle progression and its molecular mechanism in human fetal osteoblasts. CPC extracts (10 µg/ml) increased cell proliferation in the human fetal osteoblasts as compared to non-supplemented control. There was no significant change in the G1 and S phase, but a increase in the G2/M phase in 10 µg/ml and 100 µg/ml of CPC extracts group as compared to non-supplemented control. The protein expression of cyclin E, cdk 2, cyclin D, cdk 4, and cdk 6 was higher than that of control group. The level of p21 was lower than that of control. But that of pRb and p16 was not distinguished from control. These results indicate that the increase of cell proliferation by CPC extracts may be due to the increased expression of cyclin E, cdk 2, cyclin D, cdk 4 and cdk 6, and the decreased expression of p21 in human fetal osteoblasts.