Objective:　To　analyze　the　distribution　characteristics　of　blood　flow　and　wall　shear　stress　with　the　consideration　of　elasticity　of　the　artery　wall　and　to　investigate　the　biomechanical　factors　inducing　aneurismal　rupture.　Methods:　The　three-dimensional　patient-specific　internal　carotid　artery　aneurysm　model　was　constructed　based　on　two-dimensional　medical　scan　images.　The　artery　wall　model　was　created　based　on　the　statistical　data　of　human　body.　According　to　the　condition　of　the　pulsatile　blood　flow　in　human　body,　hemodynamics　in　internal　carotid　aneurysm　with　fluid　structure　interaction　was　simulated　using　finite　volume　method　and　finite　element　method.　Results:　An　obvious　vortex　flow　in　aneurismal　cavity　was　found　with　the　direction　unchanged　during　a　cardiac　cycle.　There　was　a　region　at　the　aneurismal　neck　and　aneurismal　dome　where　the　value　of　wall　shear　stress　was　relatively　high.　It　also　found　two　regions　in　the　aneurismal　neck　and　the　aneurismal　dome　where　the　value　of　Von　Mises　Stress　reached　the　maximum　locally.　In　view　of　the　material　strength,　it　should　be　easy　to　have　aneurismal　rupture　in　these　areas.　Conclusions:　The　distribution　characteristics　of　vascular　wall　stress　can　be　obtained　by　the　calculation　of　fluid　structure　interaction　to　further　predict　the　possible　position　of　aneurismal　rupture.