Objective: To explore the relationship between serum complement 1q (C1q) and C1q/tumor necrosis factor-related protein 1 (CTRP1) levels in patients with coronary atherosclerotic heart disease (CHD) and their clinical value. Methods: Case-control study.115 patients with CHD who were hospitalized in the Department of Cardiology of Ningxia Medical University General Hospital from January 2018 to November 2018 were selected as the case group, including 72 males and 43 females, aged 35-82 years, average (59.96±9.49) years old. There were three subgroups: stable angina group (SAP, n=12), unstable angina group (UA, n=69), and acute myocardial infarction group (AMI, n=34). The control group was selected from 43 healthy subjects in the same period, including 21 males and 22 females, aged 23-71 years, with an average of (45.00±10.66) years old. Serum C1q and CTRP1 levels were tested by immunoturbidimetry and ELISA, and other biochemical indicators such as triglyceride (TG) and total cholesterol (CHOL) were detected.Multiple linear regression was used to analyze the influence of various factors on C1q level. ROC curve and area under the curve (AUC) to explore the diagnostic value of C1q and CTRP1. Results: The C1q level in the CHD group (184.06±31.05) mg/L was higher than that in the control group (122.22±28.18) mg/L (t=-11.405, P<0.001). The AMI group (192.80±34.08) mg/L was significantly higher than the SAP group (169.17±27.13) mg/L (t=-2.328, P=0.021).The CTRP1 level in the CHD group [241.85(79.38)] ng/ml was lower than that in healthy control group [292.7(67.64)] ng/ml (Z=-3.64, P<0.001). Group B with higher Gensini score (t=3.672, P<0.001) and group C (t=2.529, P=0.013) had higher C1q levels than group A.After adjusting for the effects of age, sex and other indicators, C1q levels were correlated with HDL-C (β=-0.582, P<0.001),CHOL (β=0.384,P<0.001) and systolic blood pressure (β=0.142,P=0.038). The ROC curve shows that when the CHD is diagnosed, the sensitivity of C1q level >150.82 mg/L is 87%,the specificity is 88.4%, and the AUC is 0.942. The corresponding sensitivity and specificity of CTRP1 <281.80 ng/ml are 76.5% and 60.5% respectively, and the AUC is 0.688. The AUC obtained by combined predictors was 0.944, and the sensitivity and specificity were 89.6% and 86.0% respectively. When AMI is diagnosed, C1q level >178.3 mg/L, corresponding sensitivity and specificity are 70.6% and 66.1%, the AUC is 0.726, CTRP1 has no diagnostic value. Conclusions Serum C1q levels in patients with CHD are elevated, and AMI patients are higher than SAP patients; C1q may be a potential marker reflecting the severity of coronary artery disease; there is no significant correlation between serum C1q and CTRP1 in CHD patients.