Abstract: The development and characteristics of ionic liquids （ILs） in recent decades are reviewed. The mechanism for remarkable solubility of CO2 in ionic liquids and the monte carlo simulations for predicting the atomic force fields of absorptions in ILs are also summarized. The significant advantages of fixation and utilization of CO2 with ILs as absorbent，catalyst or promoter used in organic reaction，catalyzed reaction，electrochemical reaction，supported ionic liquid membranes over the conventional absorbents and the catalytic systems without ILs are discussed. Furthermore，the proposal for solving existing problems and the prospect of its application are presented.