Nanometer　Ce-W　composite　materials　have　been　prepared　by　the　method　of　freeze-drying.　Microstructure　and　surface　properties　of　materials　were　investigated　by　SEM　and　＂in　situ＂　AES　and　emission　characteristics　have　been　determined.　It　is　found　that　the　nanometer　materials　have　relatively　small　crystal　particles　with　average　dimensions　in　the　order　of　50　nm.　Due　to　the　results　of　matrix　analysis,　the　cerium　in　the　materials　is　uniformly　distributed　on　submicron　scale,　which　proves　that　the　diffusion　ability　of　cerium　has　been　increased.　Under　high　temperature,　the　active　layer　on　the　surface　thickens　simultaneously　with　the　increase　of　cerium　and　oxygen.　As　a　result,　nanometer　Ce-W　materials　exhibit　excellent　emission　characteristics　compared　with　those　of　micron-sized　Ce-W　materials.　(C)　2006　Elsevier　B.V.　All　rights　reserved.