This study deals with flow-structure coupled analysis of cerebrovascular arteries with an aneurysm of realistic geometry. Analysis models are constructed from 3D-Computed Tomography data. The flow-structure coupled analysis employs commercial solvers CFX and ANSYS to calculate unsteady movement of the artery wall subjected to pulsatile blood flow. The data transfer between the two solvers is performed by UNIX shell script. Non-Newtonian properties of blood flow is taken into account in this simulation by use of the Carreau-Yasuda viscosity model. In this study, the arterial wall of the analysis model consists of a number of shell elements with linear elasticity. The results show a close relationship between wall shear stress and blood flow during one cardiac cycle. In addition, this study investigates non-Newtonian effect for realistic model.