PURPOSE: Coronary arterial lesions after Kawasaki disease may cause coronary endothelial dysfunction without initial coronary dilatation, stenosis, and aneurysm. TTE (transthoracic echocardiography) is a non-invasive and widely used method in clinical practice. Adenosine is short acting drug and induces coronary vasodilatation. This study was designed to measure accurate coronary dysfunction by adenosine infusion. Coronary flow reserve(CFR) is defined as "the ratio of peak hyperemic to basal coronary flow velocity(CFV) in the proximal coronary vessel". CFR measurements has provided useful clinical and physiologic information in pediatric patients with congenital or acquired heart disease. METHODS: We examined 29 patients who had a history of Kawasaki disease. 19 patients discontinued low dose aspirin(5 mg/kg/d) after recovered from coronary dilatation and 10 patients have taken low dose aspirin because they had coronary dilatation. Adenosine was infused at 160 microgram/kg/min for 4 min. Diameter, velocity and integral of coronary artery were measured. RESULTS: Diameter and velocity were increased after adenosine infusion in both coronary arteries. A reduced CFR of both coronary arteries was noted in unrecovered group. CONCLUSION: CFR measured by TTE can predict the presence of significant coronary dysfunction in convalescent phase of Kawasaki disease.