Objective To study the effects of Simvastatin on the osteoblast activity of human periodontal ligament（PDL） cells. Methods The third passage human PDL were cultured in conditional mineralization medium with different concentrations of Simvastatin. The cells were divided into A group（0 mol/L）, B group（1×10-9 mol/L）, C group （1×10-8 mol/L）, D group（1×10-7 mol/L） and E group（1×10-6 mol/L）. Alkaline phosphatase（ALP） activity, osteopontin （OPN） and capability of mineralization were measured. Results Differentiation osteoblast and mineralization of human PDL were improved in all treatment groups with different concentrations of Simvastatin（1×10-9, 1×10-8, 1×10-7, 1×10-6 mol/L）. Compared with control group, statistically significant differences were found in 1×10-8 mol/L, 1×10-7 mol/L and 1×10-6 mol/L groups（P
