The absorption performance of CO2 in 1-butyl-3-methylimidazolium glycinate ([Bmim][Gly]) promoted MDEA (N-methyldiethanolamine) aqueous solution was investigated. The influences of temperature and mass fraction on CO2 solubility were determined. The time dependence of CO2 solubility demonstrated that the absorption rate of CO2 significantly increased when MDEA aqueous solution was promoted by small amount of [Bmim][Gly]. The viscosities of both CO2-unloaded and CO2-loaded MDEA-[Bmim][Gly] aqueous solutions were measured at temperatures ranging from 303.2 K to 323.2 K and calculated by using the Weiland equation. The effects of temperature, mass fraction of MDEA and [Bmim][Gly], and CO2 loading on viscosities were demonstrated on the basis of experiments and calculations. Our work showed that when the mass fraction of [Bmim][Gly] ranged from 0.10 to 0.15 and the total mass fraction of MDEA and [Bmim][Gly] was around 0.5, high absorption rate, large absorption capacity and appropriate viscosity can be simultaneously achieved. (c) 2015 Elsevier Ltd. All rights reserved.