In this study, the effect of the physical and chemical properties of various activated carbons on the SO₂ adsorption behavior was investigated. The N₂ adsorption isotherm curves at 77K were confirmed by Brunauer-Emmett-Teller, t-plot and NLDFT equations. SO₂ was adsorbed under N₂ atmosphere, and the adsorption capacity of activated carbon was measured by the breakthrough and saturation experiments in the gas phase. The specific surface area affected the adsorption capacity of saturation, and the micropores affected the adsorption of the breakthrough point. ACs were reduced during the SO₂ adsorption process to generate CO₂, and this reduction process was confirmed using Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscope-energy dispersive X-ray spectroscopy. It was expected that the adsorbed SO₂ was reduced at a specific activated site inside the pore to generate CO₂