In this study, a bubbling fluidized-bed reactor was used to study CO2 capture from flue gas using a potassium-based dry sorbent. A dry sorbent, manufactured by the Korea Electric Power Research Institute, consists of 35% of K2CO3 for CO2 absorption and 65% of supporters for mechanical strength. H2O, a reactant of the carbonation reaction, was supplied in the reactor as a form of saturated water vapor at a given temperature. The experiment of the regeneration reaction was performed by raising up to a given temperature using N2 as a fluidization gas. It was indicated that sorption capacity and regenerability of dry sorbents showed high-efficiency at 1.97 mol H2O/mol CO2 and 400 ℃, respectively. The regenerated sorbent samples were analyzed by TGA to confirm the extent of the reaction. When the regeneration temperature was 150 ℃, the regenerability of dry sorbents was about 60%, which was capable of applying those sorbents to a two-interconnected fluidized-bed reactor system with continuous solid circulation. The results obtained in this study can be used as basic data for designing and operating a large scale CO2 capture process with two fluidized-bed reactors.