The viscosities (eta) of poly(ethylene oxide)400 (PEG400), monoethanolamine (MEA)-PEG400, diethanolamine (DEA)-PEG400 and N-methyldiethanolamine (MDEA)-PEG400 aqueous solutions were measured by using the NDJ-5S digital rotational viscometer. A thermodynamic equation was used to model the viscosities and the calculated results are satisfactory. The effects of temperature, mass fractions of amines and PEG400 on the viscosities were demonstrated on the basis of experiments and calculations. (C) 2014 Elsevier Ltd. All rights reserved.