Computational fluid dynamics (CFD) is a numerical method for modeling hemodynamics, which has been applied to the study of internal carotid artery aneurysm. And the lattice Boltzmann model has received considerable interest as an efficient method of computing a variety of fluid flows, especially with complex geometrical configurations. Therefore, 3-dimensional mathematical model of interal carotid artery vessels with aneurysm based on CTA were created. Furthermore, CFD calculations were performed by using lattice BGK model with the assumption of Newtonian fluid property for blood and the rigid wall property for the vessel and the aneurysm. The results suggest that the lattice BGK model has the potential to be a useful clinical tool for the prediction of the hemodynamics in internal carotid artery aneurysm. And the geometric configuration of aneurysm is essential to the hemodynamics in aneurysm.