Objective To compare the lipid-lowering efficacy and safety of fixed-dose combination and free combination of rosuvastatin and ezetimibe in hypercholesterolemia patients who fail to achieve low-density lipoprotein cholesterol(LDL-C)goal with statin monotherapy.Methods A total of 45 hypercholesterolemia patients who switched from statin monotherapy to fixed-dose combination of rosuvastatin and ezetimibe after failing to achieve target LDL-C goal admitted at cardiological departments of First Affiliated Hospital of Sun Yat-sen University,Nanhai Fourth People's Hospital,Foshan First People's Hospital,and Guangdong Provincial People's Hospital between March and June 2024 were enrolled and served as the study group.Another 120 hyper-cholesterolemia patients who treated with free combination of rosuvastatin and ezetimibe were se-lected from Xiamen Regional Health Medical Big Data Platform with propensity score matching and served as control group.The LDL-C level,LDL-C reduction,and changes in TC,HDL-C and TG levels in 4-6 weeks after the medication switch,as well as the safety indicators(AST,ALT,CK,Cre and eGFR)were compared between the two groups.Results In 4-6 weeks after the medication switch,the patients in the study group exhibited a significant decrease in LDL-C level(1.70±0.44 mmol/L vs 2.12±0.87 mmol/L,P＜0.01),obvious LDL-C reduction[(43.17±16.11)％vs(29.14±29.13)％,P＜0.01]when compared to those of the control group.The LDL-C goal attainment rate was significantly higher in the study group than the control group(71.11％vs 45.00％,P=0.003).In addition,there were no statistical differences in the levels of HDL-C and TG and the reductions of HDL-C and TG between the two groups in 4-6 weeks after treatment(P＞0.05).The study group obtained notably lower TC level and TC reduction than the control group in the time(P＜/0.05,P＜0.01).After treatment,no statistical differences were observed between the two groups in terms of AST,ALT,CK,Cre and eGFR(P＞0.05).Conclusion Com-pared to free combination of rosuvastatin and ezetimibe,fixed-dose combination can further reduce LDL-C level in hypercholesterolemia patients who have not achieved LDL-C goal with statin monotherapy,with higher LDL-C goal attainment rate and good safety.