Abstract: A SiC coating was prepared on different graphite matrix using a simple slurry sintering method. The relationship between the microstructure and property of SiC coating and graphite substrates was experimentally investigated. It is found that the pore radius of graphite substrate has marked effect on the microstructure and property of SiC coating. A SiC gradient coating which is beneficial to improve the oxidation resistant of graphite, is expected to form on the surface of graphite substrates with the pore radius mainly in the range of 0.1-0.5 μm.