The surface properties of silicon carbide and its surface-treatment with cetyl alcohol were investigated through X-ray photoelectron spectroscopy, X-ray diffractometry, scanning electron microscopy, dispersive properties and pyrolysis in comparison with those of silicon dioxide and activated carbon. The following results were found: (1) the surface of silicon carbide was coated by silicon dioxide, and the deposited carbon and their surface functional groups were composed of ≡SiOH from SiO2 and _??_CO, ≡COH, -C=O-OH and≡CH from activated carbon, (2) The surface-treatment affected only the surface properties of silicon carbide, but not the properties of the substrate such as crystal structure, particle size and the agglomerated state of the particles, (3) The surface-treated silicon carbide with cetanol became hydrophobic, while the untreated one was hydrophilic. This fact indicates that the surface properties of silicon carbide can be effectively improved by the surface-treatment with cetanol, (4) The IR absorptions of CH2 and CH3 due to CH stretching vibrations were observed in FTIR spectra of the surface-treated silicon carbide, (5) The pyrolysis of the surface-treated silicon carbide proceeded at the temperature range from 250 to 500°C and the main pyrolysis product was cetene. This shows that the surface groups consist of alcoxy groups formed by the dehydration condensation of surface hydroxides and alcohol.