The interaction of Si3N4 with chromium was investigated under an argon or nitrogen atmosphere at temperatures from 773-1573 K. Reaction rates were determined by thermogravimetric analysis, and reaction products were examined by X-ray diffraction. Cr2N, Cr3Si, Cr5Si3 and CrSi were produced under argon, while reaction products under nitrogen were Cr2N, CrN and Cr3Si. Possible reactions between Si3N4 and chromium have been discussed thermodynamically. The initial rate obeyed a linear rate law. When chromium particles were coated with the reaction layer, the rate was described by a parabolic rate law. The reaction mechanism and the rate-determining step have been proposed.