Rare　earth　hexaboride　are　excellent　thermionic　electron　cathodes　materials　with　low　work　function,　high　emission,　high　brightness,　and　a　long　working　time.　Light　rare　earth　hexaboride　have　recently　attracted　increasing　interest　due　to　their　applications　in　electron　source　of　high　brightness　and　longevity　[1].　Among　these　hexaborides,　LaB6　was　widely　investigated　for　its　superior　properties.　However,　the　low　resistivity　(14.2　μΩ　cm　[2])　of　LaB6　is　a　disadvantage　which　makes　it　unsuitable　for　the　direct　cathode　application,　because　this　increases　the　heating　power.　Moreover,　the　traditional　hot　sintering　method　for　preparation　of　LaB6　causes　coarse　grains　and　low　emission　property,　which　is　due　to　the　long　sintering　time　and　high　temperature.　In　this　paper,　we　report　a　study　on　a　liquid　phase　reactive　spark　plasma　sintering　method　of　fabricating　the　(LaxBa　1-x)B6　compound.　Spark　plasma　sintering　(SPS)　is　a　useful　method　for　rapid　sintering　ceramic　nanopowders,　and　it　is　suitable　for　preparation　of　ultra-fine　crystal　materials.　We　substitute　the　La　partly　with　Ba,　and　it　can　be　expected　that　the　substitution　increases　the　resistivity.　Furthermore,　since　the　radius　of　Ba　is　bigger　than　that　of　Fe,　the　substitution　can　enlarge　the　lattice　constant,　and　this　will　decrease　the　work　function.　©　2010　IEEE.