Aim To detect the peripheral venous blood' concentration of interleukin-18 in patients with coronary heart disease and angina pectoris and evaluate its clinical correlation with angina pectoris. Methods Eighty hosipitalized patients were enrolled in this research. Forty cases were unstable angina pectoris, twenty cases were stable angina pectoris, twenty cases were normal controls. All patients were performed with coronary artery angiography and Doppler echocardiography. Interleukin-18 was measured with ELISA methods. Results The concentrations of interleukin-18 in patients with coronary heart disease and angina pectoris were much higher than controls', patients with coronary heart disease and left ventricular ejection fraction≤50% had higher IL-18 concentrations than those >50%, but there were no difference between unstable angina pectoris and stable angina pectoris. Conclusions The concentrtion of Interleukin-18 was increased with coronary arteriosclerosis and the decrease of left ventricular ejection fraction, but not related to the stability of atherosclerosis plaques. Interleukin-18 perhaps had important values in diagnosing coronary artery diseases.