Ethylene and propene are major products of the thermal cracking of heavy oil. Under flame-less combustion, they are oxidized in presence of large amounts of CO2 and H2O, which may affect their kinetics of oxidation. New experimental results for the kinetic of oxidation in a jet-stirred reactor (JSR) of ethylene and propene in the presence of CO2 and H2O were obtained (1 atm, 950-1450 K). Sonic probe sampling with online FTIR analyses and offline GC-TCD/FID analyses allowed the measurement of concentration profiles for the reactants and products. A detailed kinetic reaction mechanism was used to model the experiments. Good agreement with the data was obtained. Reaction paths analyses showed the important reactions influencing the kinetic of oxidation of the present fuel mixtures. Water tends to inhibit the combustion of the fuels, whereas CO2 has a small accelerating effect upon the oxidation of ethylene in fuel-rich conditions.