The isothermal kinetics and mechanisms of the oxidation of carbon felt/carbon composites were investigated by TGA and SEM. On the TG curves, the oxidation exhibits two stages at each temperature, and according to the Arrhenius curves, the oxidation temperatures are divided into two ranges. For the different oxidation stages and temperatures, the kinetic parameters and oxidation mechanisms were obtained. SEM observation not only reveals the relation between the microstructure and oxidation mechanisms, but also shows the change of microstructure of the fibers for different oxidation amounts. Modeling of the TG curves is presented by the methods of kinetic analysis and of polynomial regression of weight loss versus reduced time curves. By comparing the experimental and simulated TG curves, the two methods can better predict weight loss of the isothermal oxidation of carbon felt/carbon composites. (c) 2007 Elsevier Ltd. All rights reserved.