To provide such a new carbon-silicon carbide composite material suitable for a sliding and sealing member that a SIC layer is formed rather thick in the surface layer part of a specified position (sliding part) of a high strength carbon base body, and to provide its producing method.

This carbon-silicon carbide composite material is obtd. by silicification of the surface of at least a part (sliding part) of a high strength carbon base body to be contact with the counter material. The silicon carbide layer in the surface layer part is formed to be at least 1mm depth while uniform dispersion of a silicon carbide part in the silicon carbide layer is realized even in the depth direction. The composite material is produced by applying a slurry comprising a silicon powder, a boron carbide powder and a binder to the surface of the sliding part of a high strength carbon base body, drying and subjecting to heat treatment at ≥1,500°C in a ≤10Torr nonoxidative atmosphere.