The　reduction　of　molybdenum　oxide　doped　with　rare　earth　oxides　(RE2O3)　and　the　properties　of　molybdenum　powder　with　RE2O3　additions　have　been　studied　by　TG-DTA,　X-ray　diffraction,　temperature　programmed　reduction　(TPR),　and　X-ray　photoelectron　spectrometry　(XPS).　The　TPR　results　show　that　the　reduction　peak　of　doped　MoO3　shifts　to　lower　temperature　as　compared　with　that　of　pure　MoO3.　The　interaction　between　rare　earth　and　molybdenum　ions　leads　to　this　decrease　of　the　reduction　temperature　of　RE2O3　doped　molybdenum　oxide.　RE2O3　is　decreasing　the　particle　size　of　molybdenum　by　the　pinning　effect　of　RE2O3　at　the　molybdenum　grain　boundaries.　Moreover,　RE2O3　nanoparticles　on　the　surface　of　molybdenum　powder　increase　the　escape　depth　of　free　electrons　in　molybdenum,　decrease　the　height　of　the　characteristic　energy　loss　peak　of　molybdenum,　and　thus　increase　the　height　of　the　XPS-Mo3d　peak.　(C)　2008　Elsevier　Ltd.　All　rights　reserved.