Objective:To investigate whether simvastatin of different concentrations have influences on the functions of EPCs in vitro. Methods:Total mononuclear cells(MNCs) were isolated from human peripheral blood by Ficoll density gradient centrifugation,and then the cells were plated on fibronectin-coated culture dishes. After 7 days cultured,attached cells were isolated and assessed with a laser scanning confocal microscope. Differentiating EPCs were characterized as adherent cells double positive for DiLDL-uptake and lectin binding. EPCs were treated with simvastatin of different concentrations(0.0001,0.0010,0.0100,0.1000,1.0000 μmol/L),or LY294002(PI3K inhibitor) plus simvastatins(0.01 μmol/L ). The influences of simvastatin on EPCs’ proliferation,migration and apoptosis were assayed with MTT assay,modified Boyden chamber assay and FACS assay, respectively. Results:Simvastatin strikingly improved the ability in proliferating,migrating and anti-apoptosis of EPCs isolated from human peripheral blood(P < 0.05). Simvastatin at 0.01 μmol/L concentration reached the maximum effects on EPCs,while the concentration of simvastatin was further increased more than 0.01 μmol/L,the improvement effects showed a tendency to decline,but the effects at 0.1 μmol/L concentration were still greater than those in control group. And the influences of simvastatin on these functions of EPCs could be blocked by LY294002. Conclusion:The present study established that simvastatin could improve EPCs-蒺 proliferation,migration and anti-apoptosis capability, and the mechanism might be involved in the PI3K/Akt pathway.