The effects of heat treatment temperature (HTT) of polyacrylonitrile-based carbon f-ber (CF) on the mechanical, thermal, and tribological properties of C/C composites were investigated. It was found that HTT (graphitization) of CF affects the thermal conductivity and mechanical and tribological characteristics of C/C composites. Thermal treatment of fibersat temperatures up to 2800°C led to a decrease of the wear rate and the friction coefficientof C/C composite-based discs from 7.0 to 1.1 μm/stop and from 0.356 to 0.269, respectively. The friction surface morphology and friction mechanism strongly depended on the mechanical properties of the CFs. The relief of the friction surface of composites based on CFs with finalgraphitization was also modified,compared to that of composites based on initial fibers.This phenomenon could be explained by modificationof the abrasive wear resistance of reinforcement fibersand consequently modificationof the friction and wearing properties of composites. Correlation of the graphitization temperature with the increased flexuraland compressive strength, apparent density, and thermal conductivity of the composites was also demonstrated.