The aim of this study was to develop a useful method of analysing the oxidation behaviour of coated-carbon/carbon (coated-C/C). A few experiments were needed to explore the oxidation rate of coated-C/Cs at various temperatures, and the activation energy of oxidation in each temperature interval was determined simultaneously. Combining theoretical analysis of the values of the activation energy and the temperature at which the mechanism changes, allows specification of the quality of the protective coating. The concept of the integrity of the coating layer is also explained from the theory of mass transportation. This analytical procedure offers a method of distinguishing the effectiveness of coated-C/Cs by different processes. The mechanism of oxidation at each temperature interval is also specified.