Abstract: The microstructure and phase component of oxidation resistant MoSi₂-SiC multilayer ceramic coating were observed and analyzed. The oxidation behaviour of the coated carbon/carbon composites was studied at various temperatures below 1650℃,and the activation energy of oxidation in each temperature interval was determined simultaneously. The relationship between oxidation behaviour, microstructure and component, and also, the mechanism of oxidation and the concept of the integrity of coating layer are explained from the theory of mass transportation. This analytical procedure offers a reasonable microstructure and component of the coating. The above results showed that the MoSi₂-SiC ceramic coating for carbon/carbon composites has high oxidation resistance at temperature up to 1650℃.