Patients　with　extracorporeal　membrane　oxygenation　still　suffer　from　high　rates　of　complication　that　linked　to　the　flow　field　within　the　blood　pump.　So　it　is　essential　to　optimise　the　geometry　of　the　pump.　The　specification　of　shroud　design　is　arguably　the　necessary　design　parameter　in　the　centrifugal　pump.　However,　the　hemodynamic　performances　of　the　different　shroud　designs　have　not　been　studied　extensively.　In　this　study,　ten　different　shroud　designs　were　made　and　divided　into　two　groups　as　the　different　covering　locations　(A:　Covering　the　blade　leading　edge,　B:　Covering　the　blade　trailing　edge).　In　every　group,　six　shroud　designs　with　the　covering　proportions　of　0,1/5,2/5,3/5,4/5,1　were　made.　Detailed　computational　fluid　dynamics　(CFD)　analyses　were　performed　to　investigate　their　effects　on　hemodynamics　and　hydraulic　performance　at　the　constant　flow　condition　(4000　rpm,　5　L/min).　The　percentage　volumes　of　the　scalar　shear　stress　in　specific　threshold　(tau＜1　Pa:　Thrombosis,　tau＞9　Pa:　the　destruction　of　von　Willebrand　factor,　tau＞50　Pa:　Platelet　activation,　tau＞150　Pa:　Break　of　red　blood)　were　used　to　compare　the　blood　damage　of　the　different　shroud　designs.　Also,　the　modified　index　of　hemolysis　(MIH)　were　calculated　based　on　a　Eulerian　approach　for　different　pumps.　CFD　simulations　predicted　an　increase　in　the　pump　head,　hydraulic　efficiency,　a　fraction　of　fluid　volume　with　scalar　shear　stress　values　above　a　threshold　(9　Pa,　50　Pa,　150　Pa)　and　MIH　with　increasing　shroud　covering　proportions　from　0　to　1　in　the　same　covering　location.　Also,　these　above　results　were　higher　in　group　B　than　group　A.　This　means　that　the　risks　of　the　hemolysis,　thrombosis　and　bleeding　increased　as　the　rise　of　the　covering　proportion　and　they　were　higher　in　the　pump　whose　shroud　covers　the　blade　trailing　edge.