The desulfurization process which belongs to the gas refining part is the unit process that eliminates H2S and COS in the coal gas formed by the coal gasification part in the integrated gasification combined cycle(IGCC). In this study, natural manganese ores were selected as the raw material of the desulfurization sorbent due to economical efficiency. Initial rates for the reactions between H2S and desulfurization sorbent using natural manganese ores were determined in a temperature range of 400~800 ℃ using a thermobalance reactor. All reactions were first order with respect to H2S and were in accord with the Arrhenius equations. When sulfidation reaction was controlled by diffusion, the temperature dependence of the effective diffusivity was given by the Arrhenius equation. Activation energies and frequency factors were obtained from the product layer diffusion coefficient of various sorbents by plotting as Arrhenius equation form.