Objective To analyze the correlation of serum creatinine(Cr)/cystatin C(Cys C)ratio and monocyte/high-density lipoprotein-cholesterol(HDL-C)ratio with hypertension complicated with coronary heart disease(CHD).Methods A total of 200 hypertension patients with concomi-tant CHD admitted in our hospital from August 2021 to August 2023 were recruited and served as the observation group,and another 100 patients with hypertension during the same period served as the control group.Based on the number of vascular lesions,the patients in the observation group were divided into single-,double-and multi-vessel disease subgroups(104,75 and 21 cases).According to their Gensini score(＜30,30-90,＞90),they were also assigned into mild,moderate and severe stenosis subgroup(98,78 and 24 cases).After the fasting venous blood sam-ples were harvested from all subjects,the serum levels of Cys C,Cr and HDL-C were measured,and monocyte count was calculated,and Spearman correlation analysis was used to determine the correlation of serum Cr/Cys C ratio and monocyte/HDL-C ratio with number and severity of cor-onary artery lesions.Results The observation group had significantly higher Cr and Cys C levels,monocyte count and monocyte/HDL-C ratio,while lower Cr/Cys C ratio and HDL-C level than the control group(P＜0.01).The conditions of above indicators were more severe in the multi-vessel lesion subgroup than the single-and double-vessel lesion subgroups(P＜0.05).Similar re-sults were observed in the severe stenosis subgroup when compared with the mild and moderate stenosis subgroups(P＜0.05).Spearman correlation analysis showed that the Cr/Cys C ratio was negatively correlated with the number of coronary artery lesions and the severity of coronary ar-tery stenosis(r=-0.743,P＜0.05;r=-0.673,P＜0.05),and the monocyte/HDL-C ratio was positively correlated with the number of coronary artery lesions and the degree of coronary artery stenosis(r=0.692,P＜0.05;r=0.611,P＜0.05).Conclusion The serum Cr/Cys C ratio and monocyte/HDL-C ratio are closely associated with hypertension combined with concomitant CHD.And the Cr/Cys C ratio is negatively correlated with the severity of the disease,and the monocyte/HDL-C ratio is positively correlated with the severity of the disease in the patients.