The oxidation of methane-based fuels was studied experimentally in a fused silica jet-stirred reactor (JSR) operating at 1-10atm, over the temperature range 900-1450K, from fuel-lean to fuel-rich conditions. Similar experiments were performed in the presence of hydrogen, carbon dioxide, hydrogen and carbon dioxide, and syngas (COH2). A recently proposed kinetic reaction mechanism (Le Cong et al., 2007) for modeling the oxidation of hydrogen, CO, methane, methanol, formaldehyde, and natural gas over a wide range of conditions including JSR, flame, shock tube, and plug flow reactor was used. The chemical kinetic modeling of the present experiments was successfully performed; the computations were also in good agreement with literature laminar burning velocities, flame structures, plug-flow reactors concentration profiles, and ignition delays. Reaction paths analyses were used to delineate the important reactions influencing the kinetic of oxidation of the fuel mixtures studied here. The kinetic reaction scheme proposed helps understanding the effect of the additives, namely syngas and carbon dioxide, on the oxidation of methane.