This work proposes a new approach, based on the reaction Si3N4 + 2B(2)O(3) + 9C --> 3SiC + 4BN + 6CO, to synthesize an SiC-BN composite. The composite was prepared by reactive hot pressing (RHP), at 2000degreesC for 60 min at 30 MPa under an argon atmosphere, following a 60 min hold at 1700degreesC without applied pressure before reaching the RHP temperature. TG-DTA results showed that a nitrogen atmosphere inhibited denitrification somewhat and retarded the reaction rate. The chemical composition of the obtained material was consistent with theoretical values. FE-SEM observation showed that in situ-formed SiC and BN phases were of spherical morphology with very fine particle size of similar to100 nm.