In this study, the physical properties of each impregnated activated carbon and general activated carbon manufactured by the impregnation method and mass production method were compared before and after the SO2 adsorption test. The concentration of KOH in the basic solution used as an adhering solution was 20 wt%, and the adsorption experiment was carried out at a SO2 concentration of 100 ppm, a temperature of 120 °C, and air conditions. BET (Brunauer, Emmett, Teller), FE-SEM (Field Emission-Scanning Electron Microscope) and XRD (X-ray diffraction) were used to compare the physical properties of each activated carbon before and after the experiment. As a result of BET analysis, both before and after the experiment, the normal activated carbon had a higher specific surface area (BET) than the two types of impregnated activated carbon, but the average pore diameter was smaller. As a result of FE-SEM analysis, the porous surface of the outer surface of the activated carbon was reduced after the experiment for all three types of activated carbon. Through XRD analysis, it was confirmed that the peak intensity was small as a result of the adsorption reaction after the experiment for all three types of activated carbon.