An　intracranial　aneurysm　(IA)　is　a　pathological　dilatation　of　the　cerebral　artery　wall.　In　clinical　practice　it　is　currently　widely　accepted　that　maximum　diameter　of　IA　is　an　indicator　for　patient　whether　to　treat　or　not.　But　studies　have　demonstrated　that　maximum　diameter　is　not　a　reliable　determinant　of　IA　rupture.　According　to　the　theory　of　strength,　if　the　stress　value　exceeds　the　strength　limit　of　material,　it　will　result　in　failure.　So　wall　stress　may　be　a　better　indicator　to　predict　aneurismal　rupture　(failure).　Study　about　wall　stress　calculated　from　solid　stress　model　using　static　pressure　has　been　performed.　But　blood　flow　and　pressure　inside　IA　are　not　steady.　The　dynamic　interaction　between　the　unsteady　flow　and　wall　may　influence　the　distribution　and　magnitude　of　wall　stress.　The　objective　of　the　present　study　was　to　compare　static　and　dynamic　wall　stress　analysis　of　patient　specific　IA.　Patient-specific　model　of　cerebral　aneurysm　whose　host　artery　has　large　bending　was　created　from　CT　data.　Simulations　about　fluid　structure　interaction　model　and　static　structural　model　were　carried　out　respectively.　Commercial　software　Ansys　11　was　used　for　simulation.　The　results　demonstrated　that　FSI　can　change　local　wall　stresses　slightly.　However,　as　far　as　the　peak　wall　stress　is　concerned,　the　change　of　wall　stress　is　negligible.　Therefore　static　structural　simulation　can　be　used　to　predict　rupture　risk　of　aneurysm　if　wall　stress　was　used　as　an　indicator　of　aneurismal　rupture　and　computational　cost　can　be　reduced　greatly.　©　2010　International　Federation　for　Medical　and　Biological　Engineering.