Abstract: Objective:To explore the relationship of serum copeptin level and coronary heart disease(CHD),and its clinical significance. Methods:Coronary angiography(CAG)was performed in 94 hospitalized patients.According to coronary angiography findings,patients were divided into two groups:CHD group(n=71)and non-CHD group as control(n=23);the patients in CHD group were further divided into 3 subgroups:stable angina pectoris(SAP,n=20),unstable angina pectoris(UAP,n=19),and acute myocardial infarction(AMI,n=32);according to Gensinis score,the CHD group were further divided into 3 subgroups:mild stenosis group(n=18),moderate stenosis group(n=24),and severe stenosis group(n=29).According to the AMI patients with heart failure(HF) or not,the patients in AMI group were assigned into AMI group with HF(n=19)and AMI group without HF(n=13).Enzyme linked immunosorbent assay was adopted to detect the levels of copeptin from the serum of all patients. Results:Serum copeptin levels in CHD patients were significantly higher than those in normal control group(P0.01);serum copeptin levels in AMI patients and UAP group were significantly higher than those in control group and SAP group(P0.01);serum copeptin levels in severe stenosis patients were higher than those in control group,mild stenosis group,and moderate stenosis group(P0.01);comparing with AMI group without HF,copeptin levels in AMI group with HF were significantly higher(P0.01). Conclusions:Copeptin may be involved in stress response of patients with coronary heart disease,it may be correlated with the severity of coronary heart disease.Copeptin level is closely associated with pathology of coronary artery,it can warn the occurrence of coronary artery to happen.