Nicotine is one of the major components of cigarette smoking which causes various systemic and local diseases to human body. The purpose of the present study was to investigate the effects of nicotine on bone mineralization in human fetal osteoblasts cell line(hFOB1). To compare the alkaline ph-osphatase(ALP) synthesis, hFOBl were cultured with DMEM/F-12 1:1 Mixture and 100 pg/ml, 1 ng/ml, 10 ng/ml, 100 ng/ml, 1 ${mu}g$/ml, 10 ${mu}g$/ml, 100 ${mu}g$/ml of nicotine. And to compare the calcium accumulation, hFOB1 cultured for 23 days were quantified and photographed. ALP activity of hFOB1 exposed to nicotine was not significantly changed at a lower concentrations of nicotine, but was significantly decreased at a higher concentrations (10 ${mu}g$/ml, 100 ${mu}g$/ml) of nicotine (p<0.05). A quantified calcium acculation in hFOB1 was significantly decreased at 1,10, and 100${mu}g$/ml of nicotine (p<0.05). Significantly decreased calcium deposition was observed at 1, 10, and 100${mu}$/ml of nicotine. These results indicate that a higher concentration of nicotine show a negative effects on mineralization of hFOB1.