Cf/ ZrB2 -SiC composites were prepared using precursor in filtration and pyrolysis(PIP) technology. The thermal conductivity, coefficient of thermal expansion( CTE) and thermal shock resistance were investigated. SEM and XRD were used to analysis microstructure and phase. The result show that the composites exhibits excellent thermal shock resistance from 1 700℃ to RT. The change of thermal shock resistance is discussed.