In this study, alkanolamine was used to achieve high absorption rates for CO2 as suggested at several literatures. The absorption rates of aqueous AMP and MEA solutions with CO2, SO2, NO2 were measured using a stirredcell reactor. The reaction rate constants were determined from the measured absorption rates. The performances were evaluated under various operating conditions. As a result, the reactions with SO2, NO2 into aqueous AMP and MEA solutions were classified as an instantaneous reaction respectively. The absorption rates increased with increase of the reaction temperature and the concentration of absorbents. The simultaneous absorption rate of CO2/SO2/NO2 into 3, 5, 10 wt.% MEA at various pressure of CO2/SO2/NO2, was more increased 14~20% than AMP solution. We investigated the effect of SO2 and NO2 on the simultaneous absorption of CO2/SO2/NO2 from a flue gas. The performances were evaluated under various operating conditions in order to investigate the absorption characteristic.