The effects of rare earth on activation sintering of MoSi 2 and electric conductivity of the matrix were analyzed on the basis of a method proposed by German and Munir. The results show that the addition of rare earth could refine the powder size and obviously reduce sintering activation energy of MoSi 2 which, for rare earth/MoSi 2 system, is 83.1 kJ/mol at 1 200 ～ 14 00 ℃, about half of that of pure MoSi 2. This decreases the sintering temperature of MoSi 2 by about 200 ℃at least, and decreases the resistivity of the matrix as well. The mechanism of rare earth activated sintering of MoSi 2 is an integrated process mostly ruled by grain boundary diffusion. When the density of materials is identical, the rare earth addition is found to have no noticeable effect on the electric conductivity of MoSi 2. [ The effects of rare earth on activation sintering of MoSi 2 and electric conductivity of the matrix were analyzed on the basis of a method proposed by German and Munir. The results show that the addition of rare earth could refine the powder size and obviously reduce sintering activation energy of MoSi 2 which, for rare earth / MoSi 2 system, is 83.1 kJ / mol at 1 200-1400 ° C., about half of that of pure MoSi 2. This decreases the sintering temperature of MoSi 2 by about 200 ° C. at least , and decreases the resistivity of the matrix as well. The mechanism of rare earth activated sintering of MoSi 2 is an integrated process mostly ruled by grain boundary diffusion. When the density of materials is identical, the rare earth addition is found to have no noticeable effect on the electric conductivity of MoSi 2. [