Abstract: Objective To evaluate the efficacy and safety of evolocumab, a proprotein convertase subtilisin/kexin type 9 （PCSK9） inhibitor, in lowering LDL-C levels in patients with coronary heart disease complicated with mild renal insufficiency. Methods Clinical data of patients diagnosed with coronary heart disease complicated with mild renal insufficiency in Department of Cardiology （estimated glomerular filtration rate （eGFR） 60-90 mL/（min·1.73 m²）） were retrospectively collected. All patients were divided into two groups according to the LDL-C lowering strategy. In the experimental group （n=50）, patients were treated with evolocumab, a PCSK9 inhibitor, combined with statins （rosuvastatin calcium tablets）, and their counterparts in the control group （n=42） were treated with statins （rosuvastatin calcium tablets） alone. LDL-C level, renal function indicators, side effects and adverse cardiovascular events at 1 and 3 months were observed between two groups. Results Compared with the control group, the LDL-C level at 1 month was significantly lower in the experimental group （（1.27±0.90） mmol/L vs. （1.75±0.82） mmol/L, P < 0.05）, and the LDL-C level 3 months was even lower （（0.94±0.44） mmol/L vs. （1.53±0.53） mmol/L, P < 0.05）. However, no significant differences were noted in the changes of renal function indicators at l and 3 months between two groups （all P > 0.05）. During 3-month treatment period, no adverse reactions, such as new-onset diabetes mellitus and neurocognitive dysfunction, were observed in both groups. The incidence of cardiovascular events （readmission for unstable angina, acute myocardial infarction and repeated percutaneous coronary intervention） and other adverse reactions （rash and myalgia） did not significantly differ between two groups （all P > 0.05）. Conclusions In coronary heart disease patients complicated with mild renal insufficiency, evolocumab combined with rosuvastatin can significantly reduce LDL-C levels at 1 and 3 months and maintain high safety compared with compared to rosuvastatin alone.