The hemodynamics of the carotid artery was numerically investigated with an approach of fluid-structure interaction (FSI). To predict the blood flow and arterial deformation of carotid artery, a framework for the FSI analysis was developed by coupling computational fluid dynamics and structural analysis. Using this framework, the hemodynamics of the carotid artery was simulated with the patient-specific clinical data of the arterial geometry, pulsatile blood flow, blood rheology and arterial deformation. It is found that the hemodynamic characteristics of the carotid artery are significantly affected by its geometric factors and flow conditions, and relatively low values of the wall shear stress were observed in the post-plaque dilated region of the carotid bifurcated area, which is known to be responsible for the growth of an atherosclerotic plaque. Since the characteristics of the blood flow in a carotid artery are also affected by the hemodynamic factors, the effects of the cardiac output, distal vascular resistance and blood viscosity on hemodynamics were also numerically analyzed.