The　reduction　behavior　of　RE2O3　doped　molybdenum　oxide　and　the　effect　of　RE2O3　on　the　property　of　molybdenum　powder　have　been　studied　by　the　methods　of　TG-DTS,　X-ray　diffraction,　temperature　programmed　reduction,　and　X-ray　photoelectron　spectrum.　Experimental　results　show　that　the　interaction　between　the　rare　earth　ion　and　molybdenum　ion　leads　to　the　decrease　of　reduction　temperature　of　molybdenum　oxide　and　RE2O3　could　decrease　the　particle　size　of　molybdenum　by　the　pining　effect　of　RE2O3　on　molybdenum　grain.　Moreover,　RE2O3　nanoparticles　on　the　surface　of　molybdenum　powder　increase　the　free　length　of　inelastic　scattering　of　photo-electrons,　decrease　the　intensity　of　feature　energy　loss　peak　of　molybdenum　substrate　and　increase　the　intensity　of　MO3d　peak.