Natural manganese ores were selected as raw materials for the desulfurization sorbent because of economical efficiency and high reactivity on hydrogen sulfide. Initial reaction rates between H2S and desulfarization sorbent of natural manganese ores were determined in a temperature range of 400-800degreesC using a thermobalance reactor. All reactions were first order with respect to H2S and were expressed by the Arrhenius relation. When the 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 an Arrhenius equation form. Several additives were mixed to improve the sulfidation capacity, and NiO was the best additive. (C) 2003 Elsevier Science Ltd. All rights reserved.