The absorption performance of CO2 in 1-butyl-3-methylimidazolium lysinate ([Bmim][Lys]) promoted N-methyldiethanolamine (MDEA) aqueous solution was investigated at the temperatures ranging from 303.2 K to 323.2 K. The mass fractions of MDEA and [Bmim][Lys respectively ranged from 03 to 0.45 and 0.05 to 0.15. The viscosities of CO2-unloaded and CO2-loaded MDEA-[Bmim][Lys] aqueous solutions were measured and modeled. The influences of temperature and concentration on the absorption capacity of CO2 were determined. The effects of temperature, solution concentration and solution viscosity on the absorption rate were illustrated. (C) 2016 Elsevier Ltd. All rights reserved.