In this paper motion of some blood clots with different mechanical properties in the cerebrovascular arteries is investigated. Blood clots mostly are originated from heart or other cardiovascular arteries and by entering the cerebrovascular arteries trigger occlusion and deprive the brain’s tissue from proper perfusion. To study this phenomenon, we used a patient-specific geometry of cerebrovascular arteries and due to obtain the motion of clot and blood’s flow in cerebral arteries, algorithm of fluid-structure interactions was used. Although previous researches have not considered the effect of mechanical properties on the motion of clot, our results demonstrate the variation of the dynamic parameters of the clot’s motion by changing the mechanical properties. We show that by increasing the rigidity of the clot, their tendency for entering to the larger arteries is raised. Also other dynamic parameters like clot’s average velocity altered when the mechanical property of the clots changes. Mechanical parameters have the main role in the motion of clots and by investigating them, our sight to the mechanism of pathologies would expand, moreover, strategies of the cerebrovascular treatments would be fascinated in the future.