We report the preparation of five different ethylene-propylene-diene terpolymer-graft-maleic anhydride/calcium carbonate samples with different calcium carbonate contents by precipitation and their mechanical properties and structural characterization.(1) In this study, we tried to analyze the thermooxidative aging and the kinetics of thermooxidative degradation with retained tensile testing for various thermal-aging times at 150 degrees C and with hot-loading-recovery measurements. The results of the hot-loading-recovery measurements and retained tensile testing showed that the sample with the best crosslinked structure had the best thermooxidative-aging resistance of all the samples. The experimental results for the thermooxidative degradation kinetics showed that the sample with the best crosslinked structure had the highest activation energy of thermal decomposition. (c) 2006 Wiley Periodicals, Inc.