The kinetics of the thermal degradation and thermo-oxidative degradation of conductive styrene-butadiene rubber (SBR)-carbon black composites were investigated using thermogravimetric analysis both in nitrogen and oxygen atmospheres. Experiments were carried out at heating rates of 5, 10, 15 and 20 degrees C/min in both the atmospheres. Friedman method, Kissinger method, Flynn-Wall-Ozawa method and Coats-Redfern method have been used to determine the activation energies of degradation. The invariant kinetic parameters using the IKP method were also determined. The results showed that the thermal stability of the composites in pure nitrogen is higher than that in air atmosphere and the increase in filler loading was found to increase the thermal stability in nitrogen atmosphere. The probable degradation mechanisms of the polymer in both the atmospheres were evaluated based on Fourier Transform Infra Red Spectroscopy (FT-IR) studies.