The surface tension (c) of monoethanolamine (MEA)-poly(ethylene oxide) 400 (PEG400) and diethanolamine (DEA)-PEG400 aqueous solutions was measured by using the BZY-1 surface tension meter. The temperatures ranged from (298.2 to 323.2) K. The mass fraction of amines and PEG400, respectively, ranged from 0.20 to 0.30 and from 0 to 0.10. A thermodynamic equation was proposed to model the surface tension of the binary and ternary mixtures. The calculated results agreed well with the experiments. The effects of temperature, mass fraction of amines and PEG400 on the surface tension were demonstrated on the basis of experiments and calculations. (C) 2013 Elsevier Ltd. All rights reserved.