Aim To investigate the effects of atorvastatin on serum myeloperoxidase(MPO) and high sensitive C-reactive protein(hs-CRP) concentrations in patients with acute coronary syndrome(ACS). Methods Seventy-eight patients with ACS were randomly separated in atorvastatin treatment group and control group.The serum concentrations of MPO and hs-CRP were measured before and after treatment. Results Serum MPO and hs-CRP concentrations were significantly lower after treatment in the two groups(p<0.05).Compared with control group,serum MPO and hs-CRP concentrations were reduced significantly in atorvastatin group(p<0.05).There were no correlations between the reduction of MPO and hs-CRP(r=0.124,P=0.068). Conclusions Atorvastatin reduced serum MPO and hs-CRP concentrations in patients with ACS.These effects may explain some clinical benefits of statins in the treatment of these patients.