Background : The ophthalmic artery (OA) is the first major branch of the internal carotid artery and OA Doppler has anatomical advantage due to the absence of ultrasonic obstacles and the good sonolucency of the eye-ball. We evaluated clinical usefulness of Doppler waveform indices of OA for estimating the severity of coronary artery disease(CAD). Methods : We enrolled 263 patients who underwent diagnostic catheterization (1 Vessle Disease 100, Multivessle Disease 71, Nomal Control 92). CAD-group consisted of patients who had > 50% stenosis of major coronary arteries on CAG. For evaluation of OA blood flow velocity, We used sterile opthalmic gel, and blood flow velocity of OA was assessed with pulsed doppler. We measured Peak Systolic Velocity(PSV), End-diastolic Velocity(EDV), Mean systolic velocity(Sm), Mean diastolic velocity( Dm), Mean total velocity(MTV). Pulsatile index (PI) and Resistance index (RI),the rario of systolic to diastolic mean velocity (Sm/Dm) were measured by using in this indices. Results: MDV(Dm) were significantly lower in multivessle disease patients (control 6.86짹5.73 vs 1Vs 7.87짹5.62 vs Multi-Vs 4.8짹5.35) and the levels of Sm/Dm were significantly higher in patients (control 2.48짹2.06 vs 1Vs 2.77짹3.77 vs Multi-Vs 4.64짹7.94) with CAD-groups including 1 vessle diseaes than in controls, with multi-vessle disease groups than in those single diseases groups There were no significant differences between PSV, EDV, Sm, PI and RI. Conclusions: Among the OA Doppler flow parameters, MDV and Sm/Dm could predict the severity of CAD. especially, is useful for diagnosis of multivessle coronary artery disease ,so that could be used as another noninvasive tool for evaluating the severity of atherosclerosis and CAD.