Scandia-doped-impregnated　(SDI)　cathodes　were　fabricated　with　scandia-doped　tungsten　powders　using　spray　drying　(SD)　combined　with　two-step　reduction　in　hydrogen　atmosphere.　The　temperature-programmed　reduction　results　show　that　the　addition　of　Sc2O3　leads　to　a　decrease　of　the　reduction　temperature　of　scandia-doped　tungsten　oxide　powders.　Using　the　obtained　scandia-doped　tungsten　powders　with　homogenous　distribution　of　nanosized　scandia,　a　submicrometer　porous　matrix　cathode　composed　of　tungsten　grains　with　active　substances　distributing　uniformly　around　these　grains　has　been　obtained.　For　cathodes　with　the　above　matrices　and　impregnated　with　411　or　612　Ba,　Ca　aluminates　(named　SDI/SD-411　or　SDI/SD-612　cathodes,　respectively)　and　space　charge　limited　current　densities　of　similar　to　72.5　A/cm(2)　have　been　reliably　reached　at　900　degrees　C-b.　After　proper　activation,　the　cathode　surface　is　covered　by　a　Ba-Sc-O　active　substance　layer　with　preferable　atomic　ratios,　leading　to　its　good　emission　property.　The　average　evaporation　rate　of　8.45　x　10(-9)　gcm(-2)　s(-1)　at　1150　degrees　C-b　for　SDI/SD-612　cathode　is　the　lowest　one　among　Ba-W,　W/Re/Os-M,　SG-411　(the　scandia-doped　cathode　fabricated　by　sol-gel　method　with　impregnating　411　aluminates),　and　SDI/SD-612　cathodes.