The　influence　of　the　relative　intraatrial　anastomoses　positions　of　IVC　to　SVC　on　the　hemodynamic　performance　is　studied　for　surgical　planning.　First,　to　provide　a　theoretical　basis　for　the　clinical　treatment,　a　3D　geometry　model　including　pulmonary　artery　(PA),　left　(LPA)　and　right　(RPA)　pulmonary　arteries,　SVC,　and　IVC　is　reconstructed　from　medical　images.　Second,　based　on　virtual　environment,　three　surgical　option　models　are　sculptured　according　to　the　relative　positions　between　the　IVC　and　the　SVC　in　a　free　form　deformation.　Finally,　numerical　simulations　of　hemodynamics　are　carried　out.　The　flow　structures,　total　pressures,　power　losses,　and　flow　splits　are　analyzed　to　evaluate　the　optimal　options.　Results　show　that　the　right-IVC　model　performs　a　less　power　loss　and　relative　balanced　flow　split,　which　may　be　the　optimal　option.