The excess molar volume V-E, viscosity deviation Delta eta and excess Gibbs free energy of activation DeltaG*(E) of viscous flow have been investigated from the density and viscosity measurements of propane-1,2 diol (1) + water (2) over the entire range of mole fractions at 303.15, 308.15, 313.15 and 318.15 K. The results were fitted by Redlich-Kister equation. The system exhibited very large negative values of V-E due to increased interactions between unlike molecules or very large differences in the molar volumes of pure components at low temperature.