Abstract: Based on the reaction thermodynamics, the microstructure and energy dispersive spectrometer analysis, the interfacial solid-state reaction of SiC/Cr diffusion couple was studied at high temperature（1400-1600 ℃）. The results show that only Si and C elements diffuse into the the side of Cr metal with a thickness of 24.7 μm after heat treatment at 1400 ℃,and the thickness of the reaction layer increases rapidly with the increase of temperature. When the temperature reaches 1600℃, Cr elements also begin to diffuse to the SiC side. In the initial stage of diffusion, Cr₅Si₃ and Cr₂₃C₆ appear on the side of Cr metal. After stabilization, the phase distribution of the reactants is Cr₅Si₃C_x, Cr₇C₃ and Cr₅Si₃C_x in turn.