Abstract: Objective: To explore the clinical efficacy and safety of rosuvastatin combined with ezetimibe in the treatment of acute coronary syndrome(ACS).Methods: Eighty-five patients with ACS were randomly divided into the rosuvastatin calcium group(control group) and rosuvastatin calcium combined with ezetimibe(combination group).The serology changes after 4 weeks of treatment,and incidence rate of major cardiovascular event during 4 weeks of treatment between two groups were compared.Results: Compared with before treatment,the levels of triacylglycerol,total cholesterol and low density lipoprotein cholestorol in two groups significantly decreased after treatment(P<0.05 to P<0.01),the decreasing degree of lipid indexes in combination group was more than that in control group after treatment(P<0.01).Compared before treatment,the levels of alanine aminotransferase and creatine kinase in two groups decreased after treatment(P<0.01),the difference of the decreasing degree of which between two groups was not statistically significant(P>0.05).The incidence rate of cardiovascular event in combination group during 4 weeks of treatment was lower than that in control group(P<0.05).Conclusions: Rosuvastatin combined with ezetimibe in the treatment acute coronary syndrome can decrease the blood lipid level and incidence of major cardiovascular event,which has good efficacy and safety.