The　endwall　profiling　designed　to　reduce　secondary　flow　loss　may　change　local　pressure　which　may　influence　the　sealing　efficiency　of　rim　seal.　This　paper　presents　a　numerical　comparison　on　the　sealing　efficiency　of　rim　seal　and　the　aerodynamic　performance　of　the　blade　with　five　different　endwall　profilings　near　the　blade　leading　edge.　Three-dimensional　unsteady　Reynolds-averaged　Navier-Stokes　(URANS)　equations　coupled　with　a　fully　developed　shear　stress　transport　(SST)　turbulent　model　from　ANSYS-CFX　are　utilized　to　investigate　the　sealing　efficiency　and　the　flow　characteristics　of　turbine　rim　seal.　The　sealing　efficiency　of　rim　seal　is　compared　with　experimental　data　and　the　accuracy　of　the　presented　numerical　method　is　validated.　The　numerical　results　show　that　different　endwall　profilings　of　blade　leading　edge　can　affect　local　pressure　and　sealing　efficiency.　In　comparison　with　axisymmetric　endwall,　the　convex　endwall　profiling　makes　high-pressure　area　move　forward,　increasing　the　mainstream＇s　circumferential　pressure　fluctuation.　The　minimum　sealing　flow　rate　of　convex　endwall　profiling　is　increased　by　more　than　23%.　However,　the　concave　endwall　profiling　can　reduce　the　local　pressure　and　the　mainstream＇s　circumferential　pressure　fluctuation.　The　minimum　sealing　flow　rate　of　concave　endwall　profiling　can　be　decreased　by　more　than　14%.　However,　the　concave　endwall　profiling　enlarges　the　vortex　in　the　blade　passage　and　reduces　stage　efficiency.　©　2019,　Editorial　Office　of　Journal　of　Xi＇an　Jiaotong　University.　All　right　reserved.