Background:　The　various　components　of　the　aortic　root　maintain　a　particular　geometric　relationship　to　guarantee　unobstructed　blood　flow　across　the　aortic　valve　and　valve　competence.　Objective:　To　quantify　the　effect　of　the　position　of　the　coronary　sinus　orifice　(CSO)　on　aortic　leaflet　coaptation.　Methods:　2D　and　3D　finite　element　models　of　an　aortic　valve　and　root　were　constructed,　with　the　CSO　located　on　the　bottom　and　middle　of　the　sinuses.　ADINA　fluid-structure　interaction　solver　was　employed　to　perform　computational　simulation.　Results:　The　mean　sinus　pressure　with　left　and　right　CSO　was　1.02E+4　Pa　and　1.03E+4　Pa,　respectively,　and　the　average　leaflet　pressure　with　left　and　right　CSO　was　1.06E+4　Pa　and　1.05E+4　Pa,　respectively,　for　the　model　with　CSO　located　in　the　middle　and　bottom　of　the　sinus.　The　leaflet　summit　displacement　differences　of　the　CSO　position　on　the　bottom　and　middle　between　left　and　right　coronary　sinuses　and　none　were　11.56,　-107.57,　16.17　and　-92.86　mu　m,　respectively.　Conclusions:　The　position　of　the　CSO　affects　the　pressure　distribution　of　the　aortic　root.　The　local　high　pressure　results　in　symmetrical　deformation　of　the　three　leaflets,　and　decreases　the　risk　of　leaflet　mismatch　in　coaptation.