Abstract: To reduce the emission of CO2, an approach of absorbing CO2 from simulated flue gas by aqueous ammonia to generate ammonium bicarbonate was studied. The effect of ammonia concentration, CO2 content in flue gas and gas flow rate on the removal rate of CO2 was investigated. Results showed that with the increase of ammonia concentration in solution, the absorption of CO2 enhanced, but the content of ammonia in the exhaust gas increased as well, so the optimum mass fraction of ammonia in solution was 8%—10%; the increase of gas flow rate and CO2 content in flue gas had negative effect on the absorption of CO2, the appropriate flow rate of inlet gas was 0.6 L/min and the volume fraction of CO2 was 10%. Adding some zeolite particles in aqueous ammonia could improve the CO2 removal rate significantly. It was found that the reaction products were mainly ammonium bicarbonate.