The　morphology　of　basilar　aneurysms　is　a　crucial　factor　which　has　great　influence　on　the　hemodynamics　and　hence　the　growth,　thrombosis,　and　rupture　of　aneurysms.　No　one　has　ever　studied　the　hemodynamics　in　the　sinuous　basilar　aneurysms　(SBAs)　by　means　of　numerical　simulation.　The　objectives　of　the　work　are　twofold:　one　is　to　simulate　the　3-dimensional　physiologically　pulsatile　blood　flow　in　the　SBAs;　the　other　is　to　analyze　and　examine　the　hemodynamics　in　the　two　aneurysms,　and　assess　the　possibilities　of　rupture　for　these　aneurysms.　Geometrically　idealized　3-dimensional　fusiform　SBAs　model　generated　from　a　S-shaped　artery　was　constructed　via　CAD　software,　and　numerical　simulation　of　pulsatile　flow　in　this　model　was　performed　using　finite　element　method.　The　distributions　and　alternations　of　flow　patterns,　pressure-drops　and　wall　shear　stresses　over　a　cardiac　cycle　in　the　SBAs　were　collected,　and　the　hemodynamic　data　in　the　two　aneurysms　were　compared.　The　proximal　aneurysm　has　higher　pressure　than　the　distal　one,　and　the　proximal　aneurysm　is　subject　to　stronger　flow　strike　than　the　distal　one　during　the　deceleration　phase.　The　wall　shear　stresses　in　the　proximal　aneurysm　oscillate　more　violently　than　those　in　the　distal　one,　and　the　secondary　flow　vortices　in　the　distal　aneurysm　are　more　obvious　than　those　in　the　proximal　one　which　indicates　that　the　distal　aneurysm　is　prone　to　thrombus　development　compared　with　the　proximal　one.　These　hemodynamic　phenomena　suggest　that　the　proximal　aneurysm　in　the　SBAs　has　more　dangerous　tendency　to　aneurysmal　growth　and　rupture.