The　further　rupture　of　atherosclerotic　ulceration　plaque　is　one　of　the　main　triggers　of　the　carotid　ischemic　stroke.　However,　the　abnormal　hemodynamics　is　not　well　addressed　yet.　A　lesion-based　computational　fluid　dynamic　(CFD)　analysis　is　proposed　to　investigate　the　complex　hemodynamic　change　of　the　ulceration　plaque　that　prevails　in　patients.　The　3D　models　including　eight　groups　of　ulcerations　(six　groups　with　single　ulceration　and　two　groups　with　two　consecutive　ulcerations),　were　reconstructed　based　on　the　computer　tomography　(CT)　images,　and　the　tetrahedral　grid　was　taken　to　mesh　the　models　with　the　appropriate　numbers.　After　setting　the　boundary　conditions,　numerical　simulation　was　carried　out　to　analyze　the　pulsatile　blood　flow　in　the　models.　The　complex　flow　in　the　vicinity　of　the　ulcerations　directly　leads　to　a　significant　effect　on　the　distribution　of　the　wall　shear　stress　(WSS).　WSS　is　respectively　from　3.29　to　35.41　Pa　at　the　upstream,　from　11.90　to　41.85　Pa　at　the　downstream　ulceration,　and　18.60　and　30.60　Pa　in　the　area　between　the　two　consecutive　ulcerations.　The　rupture　from　these　regions　could　cause　the　further　rupture　of　ulceration　plaques,　particularly　at　the　downstream　ulceration　and　the　area　between　the　two　consecutive　ulcerations.　The　twisting　and　the　curling　of　the　flow　at　the　ulcerations　can　lead　to　thrombosis　which　may　break　free　later　and　go　through　the　downstream　stenosis　by　the　effect　of　the　flow.　The　different　degrees　of　WSS　in　downstream　and　upstream　ulcerations　will　damage　the　ulceration　on　the　plaque　because　of　pulling　and　stretching　forces　at　the　ulcerations.　Furthermore,　high　wall　shear　stress　gradient　(WSSG)　also　increases　the　risk　of　the　further　rupture.　Our　study　gives　a　better　understanding　in　the　further　rupture　mechanism　of　ulceration　plaques　and　provides　the　information　of　the　location　of　thrombosis　after　aggravated　rupturing,　which　can　be　referred　by　surgeons　to　improve　the　surgical　planning.