We have studied that the prediction of desulfurization efficiency by limestone in fluidized-bed coal combustor. The results were presented as follows ; Firstly, the bed temperature had a great deal of effect on the desulfurization and the optimum temperature of limestone was 850℃∼900℃. Secondly, as the velocity and temperature increased, k_s, K and the desulfurization efficiency increased. So, k_d, k_d highly depended on the air velocity and bed temperature, and k_s, k_d were 82.53 mm/sec, 0.0041/sec at 0.2 m/sec, 850℃, k_s, k_d were 125.62 mm/sec, 0.00532/sec at 0.3 m/sec, 800℃ respectively. And k_s, k_d were 143.78 mm/sec, 0.00568.sec at 0.3 m/sec, 850℃. Thirdly, as a result of desulfurization modeling, there was good agreement between theory and experiments as anthracite fraction increased. At 3.0 of optimum Ca/S molar ratio, there way very good agreement between theory and experiments.