The　preparation　of　REO-Mo　metal　ceramic　cathodes　with　fine　sub-micro　structure　on　the　basis　of　precursor　rare　oxide　doped　molybdenum　powder　synthesized　by　a　sol-gel　and　two-step　method　was　discussed.　It　was　found　that　the　whole　preparation　process　of　REO-Mo　cathodes　was　typically　powder　metallurgy　process　and　so　the　quality　of　the　precursor　powder　was　of　importance.　The　superfine　rare　earth　oxide　doped　molybdenum　powder　was　successfully　prepared　by　the　sol-gel　method　and　two-step　reduction　method.　The　optimal　sintering　temperature　for　SPS　method　was　1400°C.　Rare　earth　oxides　were　uniformly　distributed　in　the　sintering　bodies　with　sub-microstructure.　Results　show　that　the　amendence　of　microstructure　led　to　improvement　of　secondary　emission.