Aneurysm is a vascular disorder characterized by abnormal focal dilation of an artery which is considered as a serious and potentially life-threatening condition. An estimated 2%–5% of the general population is affected by intracranial aneurysms. Through computational fluid dynamic (CFD) investigation, this study aims to learn the flow characteristic on aneurysm afflicted common carotid artery (CCA). This study focused on the velocity, wall shear stress (WSS) and sensitivity of blood viscosity of the CCA flow. CFD method was done to 3 simplified model of CCA which were normal, saccular aneurysm, fusiform aneurysm CCA model. The simulation was done with different blood viscosity model which were Newtonian and non-Newtonian. The high velocity area of blood flow has corresponding effect to the increase of the WSS distribution to the wall of the geometry. The results also showed at certain value of low velocity area, WSS distribution for different blood viscosity model was deviated significantly.