Abstract: Sulfur dioxide oxidation catalyzed by activated carbon in a slurry reactor (at room temperature and atmospheric pressure) was studied . The postulated reaction mechanism was indirectly tested by varying the composition of oxygen and sulfur dioxide in inlet gas and by measuring the volume-averaged oxidation rate of sulfur dioxide of small particles (the resistance of mass transfer is of minor importance), and furthermore, the model parameters were evaluated by varying the concentrations of slurries of activated carbon , the sizes of particle as well as the reaction temperature.