Three-dimensional carbon fiber reinforced SiC-ZrC composites (C/SiC-ZrC) were prepared by chemical vapor infiltration (CVI) combined with precursor infiltration and pyrolysis (PIP) process for ultra high temperature application, and the properties of C/SiC-ZrC composites with different SiC contents were investigated. The results show that with the of increased the SiC content, the flexural strength of the composites decreased gradually, the oxidation properties increased, and the mass loss rate and linear recession rate in oxyacetylene torch environment decreased first and then increased. The changes of the oxidation and ablation properties were caused by the formation of SiO₂ glass.