The　secondary　electron　emission　property　and　microstructure　of　La2O3-Y2O3-Mo　cermet　cathode　have　been　studied.　It　shows　that　the　cathode　prepared　by　Sol　Gel　doping　method　has　fine　microstructure　containing　rare　earth　oxide　(RE2O3)　nanoparticles　and　uniform　distribution　of　different　substances.　Auger　Electron　Spectroscopy　(AES)　depth　profile　result　shows　that　an　RE2O3　layer　about　28　nm　in　thickness　could　be　formed　on　the　cathode　surface,　which　plays　an　important　role　in　the　emission.　Pre-activation　of　the　cathode　is　favorable　for　the　improvement　of　emission　property.　La2O3-Y2O3-Mo　cathode　pre-activated　exhibits　good　secondary　emission　property.　The　secondary　emission　yield　could　reach　5.24,　about　1.8　times　higher　than　that　of　original　cathode.　The　enhancement　on　the　conductivity　of　materials　resulting　from　the　pre-activation　is　favorable　for　the　replenishment　and　transport　of　electrons,　thus　the　secondary　emission　property　of　the　cathode　could　be　improved.　(C)　2010　Elsevier　B.V.　All　rights　reserved.