As　for　the　scandate　cathode,　the　performance　of　Sc　atom,　including　the　adsorbability　and　diffusivity,　plays　an　important　role　in　the　emission　property　and　emission　stability　of　the　scandate　cathode.　W　is　the　most　widely　used　matrix　metal　in　thermionic　scandate　cathodes,　however,　the　cathode　suffers　from　the　recovery　of　scandium　after　ion　bombardment.　Herein,　the　adsorption　properties　and　diffusion　performance　of　Sc　atom　on　the　surfaces　of　W,　Ir,　Os,　Re　and　Ru　are　systematically　studied　with　the　density　functional　theory　(DFT).　It　is　found　that　the　adsorbabilities　and　diffusivities　of　Sc　atom　on　the　surface　of　W,　Ir,　Os,　Re　and　Ru　are　in　the　order　as　W　(0　1　1)　＜　Re(0　0　0　1)　＜　Ru(0　0　0　1)　＜　Os(0　0　0　1)　＜　Ir(11　(2)　over　bar1)　and　Ir(11　(2)　over　bar1)　＜　W(0　1　1)　similar　to　Os(0　0　0　1)　＜　Ru　(0　0　01)　＜　Re(0　0　01),　respectively.　The　adsorbabilities　and　the　diffusivities　of　Sc　atom　on　the　surface　of　Re　and　Ru　are　higher　than　those　on　the　surface　of　W,　which　suggests　that　Re　and　Ru　are　the　potential　materials　to　be　the　matrices　or　the　coatings　of　scandate　cathodes　to　improve　the　ion　bombarding　insensitivity　and　electron　emission　recovery　of　the　cathode.