Objective:To explore the effectiveness and safety of simvastatin combined ezetimibe in patients with acute coronary syndrome (ACS).Methods:A total of 124 ACS patients complicated low density lipoprotein cholesterol (LDL-C)>100 mg/dl were selected from our hospital from May 2012 to May 2013. They were randomly and equal-ly divided into rosuvastatin group (received rosuvastatin 20mg/d)and combined treatment group (received simvasta-tin 40mg/d plus ezetimibe 10mg/d),both groups were treated for one month.Blood lipid levels and incidence rates of adverse reactions were observed in two groups.Results:Compared with before treatment,after one-month treat-ment there were significant reductions in levels of LDL-C,total cholesterol (TC)and triglyceride (TG)and signifi-cant rise in levels of high density lipoprotein cholesterol (HDL-C)in both groups (P <0.01 all),and there were no significant difference in all above blood lipid levels between two groups (P >0.05).Incidence rate of myalgia in combined treatment group was significantly lower than that of rosuvastatin group (4.8% vs.17.7%,P =0.023), but there were no significant difference in incidence rates of other adverse reactions between two groups (P >0.05 all).Conclusion:It′s effective and safe to use simvastatin combined ezetimibe in patients with acute coronary syn-drome,which is worthy extending.