This study investigated the association of circulating IGFBP1 level with the severity of coronary artery lesions in patients with unstable angina. Materials and Methods. In 112 consecutive patients with clinically diagnosed unstable angina, admitted from July 2014 to July 2015, we studied the correlations of circulating IGFBP1 and the severity of coronary artery disease (CAD). Results. All patients underwent scheduled coronary angiography, and 67 cases were diagnosed with critical and 45 with noncritical CAD. Here, IGFBP1 is linked to angina pectoris.