Using PAN-based pre-oxidized fiber integral felt as reinforcement, the porous C/C preforms were fabricated by carbonization and isothermal CVI, and then C/C-Cu composites were manufactured by gas pressure infiltration technique which introduced copper into the porosity of C/C preforms. The ablative properties of C/C-Cu composites were tested by H2-O2 ablation method. The micro-morphology and constitutions in different ablative regions were analyzed by SEM and EDS. The results indicate that the ablative performance of C/C-Cu composites with 0.96g/cm3 density is excellent due to low linear and mass ablation rate. The ablative macro-morphology is composed of significant pit as central region in which the ablative mechanisms are oxidation of C/C preform and mechanical erosion of copper. Thermal oxidation and mechanical erosion of copper result in copper concentration in transition region, and black color surface in marginal region is due to oxidation of C/C preform. In order to improve the ablative performance of C/C-Cu, "pinning" effect of C/C preform should play an important role which can prevent copper from flowing by flame at high temperature.