Ionic liquids (ILs) are investigated in-many studies to capture CO2 in recent years. However, almost all of these studies carried out the absorption of CO2 by ILs at relatively low temperatures (lower than 333.15, K or even around room temperature). Besides, the viscosity of Its increases dramatically after absorbing CO2, which could reduce the absorption efficiency significantly. Reversible and efficient absorption of CO2 at high temperatures was investigated by IL of tetraethylenepentamine acetic acid ([TEPA]Ac) and polyethylene glycol 200 (PEG-200) mixtures with low viscosity. The results showed that the absorption capacity of [TEPA]Ac/PEG-200 mixtures achieved 1.24 mol of CO2/mol of [TEPA]Ac at 353.15 K at ambient pressure (1.01 bar):. The mixtures could be easily regenerated by bubbling dried N-2 through them. The addition of PEG-200 in [TEPA]Ac could increase the efficiency-of absorption and desorption significantly. Furthermore, the solubility data of CO2 in the [TEPA]Ac/PEG-200 mixtures at T = 353.15, 368.15, 383.15, and 398:15 K under different pressures were measured, and the solution enthalpy (Delta H-sol) and solution entropy (Delta S-sol) were calculated. Under all of the conditions, the negative value of Delta H-sol inditated that the capture process, is exothermic. The process of CO2 tapture described' that using, [TEPA]Ac/PEG-200 mixtures is a promising approach for CO2 absorption with high reversibility and-excellent absorption property at a relatively high temperature.