Abstract: 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.