The　aim　of　the　present　experimental　study　is　to　determine　the　effects　of　sinotubular　junction　diameter　on　artificial　bioprosthesis　valves.　An　experimental　study　was　performed　for　aortic　root　models　with　different　sinotubular　junction　taper　under　pulsatile　flow　condition.　The　sinotubular　junction　diameters　were　modified　to　create　four　models　with　different　sinotubular　junction　tapers　with　0,　1,　3　and　5　degrees,　respectively,　using　three　dimensional　printing　techniques.　After　installing　the　testing　bioprosthesis　valve　on　the　aortic　root　models,　we　conducted　experiments　of　the　pulsatile　flow　testing　with　different　stroke　volume　in　the　pulsatile　circulation　simulation　system.　The　testing　condition　was　set　at　the　pulse　frequency　of　70　beats/min　and　the　stroke　volume　of　2-7　L/min.　The　status　of　the　valves　in　10　continuous　pulse　cycles　was　tested　and　the　average　results　were　obtained　for　each　stroke　volume.　The　results　of　testing　showed　that　the　mean　transvalvular　pressure　gradients　agreed　well　with　the　national　standard,　and　all　smaller　than　10　mm　Hg.　The　sinotubular　junction　taper　had　an　influence　on　regurgitation　fraction　of　the　artificial　bioprosthesis　valve.　The　smaller　sinotubular　junction　taper　showed　beneficial　effect　to　decrease　the　regurgitation　fraction.　In　the　case　of　smaller　stroke　volume,　the　smaller　sinotubular　junction　taper　was　beneficial　to　increase　the　effective　valve　orifice　area.　In　the　case　of　larger　stroke　volume,　the　larger　sinotubular　junction　taper　was　beneficial　to　increase　the　effective　valve　orifice　area.　This　study　indicates　that　a　doctor　should　consider　the　smaller　sinotubular　junction　taper　in　the　case　of　smaller　stroke　volume　more.　In　the　case　of　larger　stroke　volume,　the　doctor　should　consider　the　larger　sinotubular　junction　taper　more.　Copyright　©　2017　by　Editorial　Office　of　Journal　of　Biomedical　Engineering.