Aim To observe the efficacy of atorvastatin combined with ezetimibe in patients with acute coronary syndrome. Methods 306 patients with acute coronary syndrome were randomly divided into atorvastatin routine-doze group （n98, atorvastatin 20 mg/d）, atorvastatin double-doze group （n103, atorvastatin 40 mg/d） and co-administration group （n105, atorvastatin 20 mg/d+ezetimibe 10 mg/d）. Levels of total cholesterol（TC）, triglyceride（TG） and low density lipoprotein-cholesterol（LDLC） were detected before and after 24-week therapy. The adverse reactions and cardiovascular events were also observed during the treatment. Results Compared with baseline, the levels of TC, TG and LDLC were reduced after 24 weeks in the three groups, and the TC,TG,LDLC levels in co-administration group were more significantly reduced than atorvastatin routine-doze group and atorvastatin double-doze group（TC: 2.51±0.51 mmol/L vs 3.22±0.53 mmol/L and 3.10±0.63 mmol/L, P<0.05TG: 1.12±0.30 mmol/L vs 1.67±0.39 mmol/L and 1.53±0.27 mmol/L, P<0.05 LDLC: 1.58±0.27 mmol/L vs 2.11±0.33 mmol/L and 2.01±0.31 mmol/L, P<0.05） The LDLC target rate in co-administration group was significantly higher than those in atorvastatin routine-doze group and atorvastatin double-doze group（69.5% vs 43.9% and 48.5%, P<0.05）. The incidence of adverse reactions in co-administration group was lower than that in atorvastatin double-doze group （P<0.05）. The incidence of cardiovascular events （recurrence of angina pectoris and acute myocardial infarction） in co-administration group was lower than those in other two groups （P<0.05）. Conclusions The combined atorvastatin and ezetimibe therapy after ACS had a good security, and was superior to atorvastatin alone on improving lipid levels and reducing the incidence of cardiovascular events.