Abstract: Carbon fiber-reinforced carbon composites (C/ C), carbon fiber reinforced-carbon and silicon carbide binary matrix composites (C/ C-SiC) and carbon fiber reinforced carbon-silicon-zirconium-oxygen matrix composites (C/ C-Si-Zr-O) were prepared through a combination of chemical vapor infiltration (CVI) and polymer impregnation pyrolysis. The microscopic morphology, phase structure, mechanical properties and thermal conductivity of the C/ C, C/ C-SiC and C/ C-Si-Zr-O composites were investigated by SEM, XRD, EDA and laser flash thermal conductive measurements. Results showed that the flexural strength of the C/ C-Si-Zr-O composites was higher than that of the C/ C and the C/ C-SiC composites, which can be ascribed to their energy absorption mechanisms, such as fiber debonding and pullout from the matrix. The C/ C composites possessed the highest thermal conductivity (69. 09 W/ (m·K) in the parallel direction and 25. 28 W/ (m·K) in the vertical direction), which can be accounted for by the high thermal conductivity of the pyrocarbon matrix, a low porosity of the composites, a long phonon mean free path and fewer structural defects