Background: The intima-media thickness(IMT) of common carotid artery(CCA) has been the good index of the atherosclesosis. But the clinical correlation between carotid IMT and the severity of coronary artery disease (CAD) is relatively poor. The aim of this study was to test the correlation of intimal echogenic thickening(IT) and plaque burden of culprit lesion on coronary IVUS. Methods: In 33 patients (M:F=20:13, mean age 63짹8 yrs) underwent coronary angiogram, the results of carotid doppler was compared with those of IVUS. The carotid IT was defined as a thickened echogenic superficial layer(Figure) at the far wall of CCA using 15MHz linear array transducer. The thickness of this layer was measured five times repeatedly with inverted zoom image and was averaged. The plaque burden was defined as maximum percent plaque area at culprit lesion on IVUS. The intimal thickening ratio was defined as a ratio of IT on IMT. Results: 1.The mean IT, mean carotid IMT and mean ratio of IT and IMT were 0.27짹0.03mm, 0.85짹0.22mm and 33짹7%. 2. The mean maximum percent plaque area at culprit lesion was 68.43짹11%. 3. The IT was closely related to maximal percent plaque area(r=0.34, p<0.05). 4. The IT was not related to other IVUS parameters or the risk factors of CAD. Conclusions: Our data suggest the intimal echogenic thickening of CCA using high frequency transducer can predict the plaque burden in culprit vessel and the measurement of intimal layer of CCA should be considered as a novel method of the evaluation of atherosclerosis.