A new SiC coating method on multi-walled carbon nanotubes has been developed by using the reaction between SiO vapor and carbon at 1250℃~ 1450℃ in vacuum. The growth mechanism of SiC layer was clarified. The SiC coating improved significantly the oxidation resistance of carbon nanotubes. SiC-coated carbon nanotubes were applied as reinforcements to wear resistant materials. Dense SiC-coated carbon nanotubes reinforced SiC composites were successfully fabricated by spark plasma sintering. These composites showed superior mechanical properties.