A rigorous thermodynamics model of CO2 absorption by monoethanolamine (MEA) is essential to model treatment of acid gases by aqueous MEA. In this study, the statistical associating fluid theory (SAFE) is applied for modeling the CO2 absorption by MEA. The pure component properties of MEA, vapor-liquid equilibrium properties of binary MEA-H2O and ternary MEA-CO2-H2O are evaluated by considering the SAFE expression of Huang and Radosz (SAFE-HR). Consequently, pure component and binary interaction parameters of the SAFT-HR equation of state (EOS) for MEA are calculated utilizing the experimental data. The association scheme 2B is chosen with examining different association schemes 2B, 3B and 4C, and considering the capability of the model in prediction of pure component properties. It is also assumed that activities of species in chemical equilibrium equal to their mole fractions. The model predictions show a good agreement with the experimental data. Meanwhile, absolute average deviation percentage of ternary MEA-CO2-H2O system by the SAFE-HR EOS is 34.71% which it is less than 36.42% and 42.29% for the PC-SAFE EOS and e-NRTL model, respectively. (C) 2017 Elsevier B.V. All rights reserved.