The crystallization behavior of a new type of ceramic matrix composites, three-dimensional silica fiber reinforced silicon nitride matrix composite prepared by perhydropolysilazane infiltration and pyrolysis, was investigated by X-ray diffractometry and Fourier transform infrared spectroscopy. With the post-annealing treatment of the amorphous as-received composite at elevated tempertures of 1400 and 1600 degrees C in nitrogen atmosphere, there was remarkable suppression of the crystallization of polymer-derived silicon nitride ceramic matrix into alpha-Si3N4 and silica fibers into alpha-cristobalite which was probably attributed to the phase of silicon oxynitrides originating from the strong fiber/matrix interfacial chemical reaction. (c) 2005 Elsevier B.V. All rights reserved.