The mass transfer performance of CO2 absorption into blended N,N-diethylethanolamine (DEEA)/ethanolamine (MEA) solutions was investigated using a lab-scale absorber (H=1.28 m, D=28 mm) packed with Dixon ring random packing. The mass transfer coefficient K(G)a(v), the unit volume absorption rate phi, outlet concentration of CO2 (y(CO2)), and the bottom temperature T-bot of CO2 in aqueous DEEA/MEA solutions were determined over the feed temperature range of 298.15-323.15 K, lean CO2 loading of 0.15-0.31 mol/mol, over a wide range of liquid flow rate of 3.90-9.75 m(3)/m(2)-h, by using inert gas flow rate of 26.11-39.17 kmol/m(2)-h and 6-18 kPa CO2 partial pressure. The results show that liquid feed temperature, lean CO2 loading, liquid flow rate, and CO2 partial pressure had significant effect on those parameters. However, the inert gas flow rate had little effect. To allow the mass transfer data to be really utilized, K(G)a(v) and y(out) correlations for the prediction of mass transfer performance were proposed and discussed. (c) 2017 American Institute of Chemical Engineers AIChE J, 63: 3048-3057, 2017