Chemical absorption mechanism of sulfur dioxide into the slurry containing fine limestone particles was analyzed theoretically by a two reaction planes model（three zone model）. As an experimental verification of the model, enhnncement factors for the liquid film mass transfer coefficients, which were obtained by the absorption using a stirred tank absorber with a plane gas-liquid interface at 20 ℃, were compared with the values predicated theoretically. It was shown that the absorption rates can be satisfactorily predicted by the proposed model. The data of absorption rate indicate that it is necessary to enhance the solid dissolution in order to improve the absorption rase. Blinding in the liquid film as well as in the bulk slurry must be considered significantly when the limestone particle is much smaller than the thickness of liquid film.