Abstract: According to the working requirements of hypersonic spacecrafts，reusable space vehicles and next generation rocket engines operating under the ultra-high temperature condition，a proposal to improve the anti-ablative property of 2D C/SiC composites by introduction of ZrB₂ was presented. 2D C/SiC-ZrB₂ composites with different ZrB₂ contents were prepared via precursor infiltration and pyrolysis (PIP) process，and the mechanical properties and anti-ablative properties and the microstructures were investigated. The result s show that the mechanical properties (flexural strength and flexural modulus) of the composites decrease with ZrB₂ content increase，but the anti-ablative properties are greatly improved. The sample with 19.4vol% ZrB₂ has the flexural strength of 242.6MPa and flexural modulus of 37.1GPa. After ablation for 90s in an oxygen-acetylene torch environment , the surface temperature of the sample is as high as 2329℃，and the mass loss rate and the linear recession rate are as low as 0.005g/s and 0.015mm/s，respectively.