Abstract: In order to improve the anti-ablation property of carbon/carbon(C/C) composites, ZrC-Cu-C/C composites were fabricated by reactive melt infiltration using C/C composites with the porosity of 38% as preforms and Zr-Cu mixed powders as reactive infiltrators. The effect of infiltrator composition on the ablation resistance of ZrC-Cu-C/C composites was investigated by the test of oxyacetylene flame ablation, and the phase composition and microstructure of the ZrC-Cu-C/C composites before and after ablation were analyzed by XRD, SEM and EDS. The results show that the composites are composed of C, ZrC, Cu and residual Zr before ablation, while there exist C matrix, ZrO₂, CuO and Cu₂O as well as remnant ZrC and Cu in the surface after ablation for 20 s. Both the linear recession rate and mass loss rate of the composites decrease first and then increase with increasing the content of Zr in infiltrators. The ZrC-Cu-C/C composite fabricated with 60% Zr-Cu(mass fraction) exhibits the best anti-ablation property, whose linear recession rate and mass loss rate are 0.001 8 mm·s^-1 and 0.001 3 g·s^-1, respectively. The ablation mechanisms of the ZrC-Cu-C/C composite are the combination of thermo-physics ablation (based on sublimation of C, melt of ZrO₂ and vaporization and sublimation of Cu), thermo-chemical ablation (oxidation of ZrC and C) and mechanical denudation (erosion of the flame).