In this study, corrosion in the carbon capture and storage process was investigated by the weight loss method using aqueous potassium carbonate as an absorbent. Potassium carbonate, in combination with CO2 and H2O, was converted to carbonate and bicarbonate that increased the corrosion. All experiments were conducted using carbon steel (JIS SS41) specimens, and the corrosion characteristics were evaluated at elevated temperatures. The effects of the organic corrosion inhibitors were explored at different concentrations, and 1,2,3-benzotriazole and ammonium thiocyanate proved to be the best inhibitors with maximum protection efficiencies of 99.5% and 90.0%, respectively, at a concentration of 1.0wt%. In addition, rate promoters did not degrade the inhibitors.