Carbon fiber reinforced Si-C-N matrix composite(C/Si-C-N) with a Si-O-C interlayer (C/Si-O-C/Si-C-N) was fabricated via CVI and PIP process. The flexural behaviors of C/Si-O-C/Si-C-N were investigated using the three-point-bending method and the SEM technique. The results indicated that the flexural strengh of the C/Si-O-C/Si-C-N increases with increasing temperature and the modulus of the composite is essentially unchanged. The strength of C/Si-O-C/Si-C-N is comparable to that of C/PyC/Si-C-N, and the role of Si-O-C interlayer in C/Si-C-N can rival that of the PyC interlayer. The weaker interfacial bonding and the larger thickness of Si-O-C interlayer make a contribution to this at RT while the thinner interlayer and unstable structure of Si-O-C interphase do it above 1300 degrees C. [GRAPHICS] .