Aim To study the plasma level of macrophage inflammatory protein-1α(MIP-1α) in patients with coronary atherosclerotic heart disease(CHD),and the correlation of MIP-1α with coronary atherosclerotic lesion severity. Methods The plasma levels of MIP-1α were measured by enzyme linked immunosorbent assay(ELISA) in 25 cases of control group and 84 cases with CHD(including 26 cases with stable pectoris angina(SAP),30 with unstable angina pectoris(UAP),and 28 with acute myocardial infarction(AMI)). All patients with CHD were taken coronary artery angiography to obtain the branch numbers of coronary lesion and Gensini coronary scoring,then the correlations were analysed between MIP-1α levels and the lesion severity of coronary lesion with Gensini coronary scoring system. Results The plasma level of MIP-1α in patients with CHD were significantly higher than that in control group(P<0.05).The plasma levels of MIP-1α were graduly increased among SAP group,UAP group and AMI group,and among mild,moderate and severe coronary lesions groups(all P<0.05),but had no obvious change in different impaired coronary branch number groups of CHD(P>0.05).The plasma levels of MIP-1α were positivly correlated with Gensini coronary scoring system(r=0.28,P<0.05). Conclusion The plasma level of MIP-1α were significantly elevated in CHD patients and could possiblly efficiently assess the severity and stability of coronary atherosclerotic lesion.