The　preparation　of　a　rare-earth　tungsten　thermionic　emission　materials　(La-W),　activated　with　nanoscale　oxide,　and　the　relationship　between　there　surface　composition　and　electron　emission　performance　were　investigated.　The　La-W　materials　surface　was　analyzed　by　means　of　Auger　electron　spectroscopy　(AES)　PHI550.　With　a　standard　parallel-plate　diode　configuration　in　a　high　vacuum　chamber,　electron　emission　was　measured　by　a　computer-control　automatic　electron　performance　surveyor.　Results　show　that　an　excess　La　active　layer　was　formed　at　high　temperature,　which　may　do　good　to　the　electron　emission.