Backgrounds: The aorta plays a central role for a modulator in whole cardiovascular system by its elasticity. If the elasticity was decreased, aortic distensibility was also decreased and stiffness index was elevated. In this study, we investigated the relationship between aortic distensibility calculated from descending thoracic aorta and intima media thickness (IMT) from aorta and carotid artery which was known as a surrogate maker for atherosclerosis and a predictor of cardiovascular events. Methods: A total of 500 patients with acute ischemic stroke were enrolled in this study. Most of patients were performed transesophageal echocardiography for detection of embolic sources. We evaluated the association of arterial stiffness index, calculated by distensibility of descending thoracic aorta and systemic blood pressure, and aortic IMT as well as carotid IMT with age, sex, potential vascular risk factors, and cardiac function by echocardiography. Results : Arterial stiffness index significantly correlated with IMT of descending thoracic aorta and carotid artery (r=0.279, p=0.014, r=441, p<0.001). It also correlated with age (r=0.410, p=0.001) and hypertension history (r=0.341 p=0.003). Arterial stiffness index significantly negative correlation with common carotid artery blood flow peak systolic velocity (r=0.-0.248, p=0.010). A stepwise multivariate regression analysis demonstrate that arterial stiffness index was independently associated with carotid IMT (棺=0.308, p=0.013), whereas aortic IMT was not an independent predictors of aortic distensibility. Conclusion : Arterial stiffness index by using distensibility of descending thoracic aorta significantly correlates with other proven surrogate for atherosclerosis such as aortic and carotid IMT. Aortic distensibility is more closely associated with carotid IMT than aortic IMT in the Patients with Ischemic Stroke.