This study compares two different impregnating methods to investigate the influence of carbonization rate on the tribological properties of carbon/carbon (C/C) composites. The experimental results indicate that the bulk density, hardness, infiltration efficiency and friction coefficient of pressure impregnating specimens are higher than those of vacuum impregnating specimens. In comparison with the vacuum impregnating specimens, the pressure impregnating specimens also show the lower apparent porosity and weight loss. Studies on the tribological properties of the specimens with different carbonization rate show that the specimens with the higher carbonization rate exhibit the lower bulk density and infiltration efficiency, but the higher porosity and friction coefficient. These results are attributed by the defect induced by the thermal stress during the higher carbonization rate process. In addition, the pressure impregnating method produces a more notable effect on the properties of C/C composites than that of the carbonization rate.