Abstract: Objective: To evaluate the changes of serum stromal cell-derived factor-1α(SDF-1α) levels in coronary heart disease,and the correlation between SDF-1α and severity of coronary lesions. Methods: By ELISA,the levels of SDF-1α from 32 patients with acute myocardial infarction(AMI),18 patients with unstable angina pectoris(UAP),20 patients with stable angina pectoris(SAP) and 23 subjects without coronary heart disease(CHD) as control were measured. The patients with angina pectoris,control group and some patients with AMI were underwent coronary angioplasty(CAG). The patients who performed CAG with CHD were divided into three groups according to the severity of coronary artery stenosis:minor group(n=11); moderate group(n=15) and severe group(n=20). The levels of serum SDF-1α were compared with 23 controls. Results: The levels of Serum SDF-1α in control group,SAP group,UAP group,AMI group were successively decreased,and the levels of SDF-1α were lower in the severe and moderate groups than those in control and minor groups(P < 0.05-P < 0.01). Conclusions: Lower levels of SDF-1α were expressed in coronary heart disease,serum levels of SDF-1α were correlated with the severity of coronary artery disease and the stenosis degree of coronary arteries.