Abstract: Objective To investigate the effect of atorvastatin-a HMG-CoA reductase inhibitor on the expression and activity of matrix metalloproteinase-9 (MMP-9) and tissue factor(TF) on human monocytes induced by Oxidized LDL (oxLDL).Methods Human monocytes-derived macrophages were incubated with oxLDL in presence or absence of different concentration atorvastatin.At the end of incubation,MMP-9 expression and its activity was assessed by ELISA and zymography analysis respectively,and TF expression and its procoagulant activity was assessed by ELISA and a one-stage clotting assay respectively. Results The results showed that atorvastatin inhibited human monocytes-derived macrophages proliferation in a methods of the concentration-dependment,which can be eliminated by adding 100μmol/L mevalonate. 0.1μmol/L and 0.5μmol/L atorvastatin can inhibit MMP-9 expression (1.32±0.06 VS 2.57±0.06μg/L，P＜0.05；1.25±0.04 VS 2.57±0.06μg/L，P＜0.05，respectively)and its activity of human monocytes-derived macrophages significantly,and inhibit TF expression(3.34±0.66 VS 5.78±0.86μg/L，P＜0.05 ；2.20±0.60 VS 5.78±0.86μg/L，P＜0.05，respectively) and its procoagulant activity in a methods of the concentration-dependment.Conclusion Atorvastatin inhibit the proliferation of human monocytes-derived macrophages,and also inhibit MMP-9 and TF expressions and their activities induced by oxLDL,which can lead to collagen degradation and blood clotting.