Abstract: According to flue gas desulfurization processes with activated carbon, several factors affecting the catalytic reaction rate of activated carbon for flue gas desulfurization were investigated on the basis of the experiment of adsorbate concentration curves along the bed. It is found that SO₂ concentration and CO₂ volume fraction have significant influences on the catalytic reaction rate, and SO₂ concentration is the primary factor. With increasing SO₂ concentration, the catalytic reaction rate increases significantly, but it does not increase at high SO₂ concentration. While the CO₂ volume fraction increases from 0 to 15%, the catalytic reaction rate decreases by 30% linearly, indicating that CO₂ plays a linear inhibition role in the catalytic reaction. The flue gas velocity between 0.14 m·s^-1 and 0.3 m·s-1 has no significant effect on the catalytic reaction rate.