Densities of methanol + trimethyl phosphate binary mixtures were measured over a temperature range of (293. 15 to 333. 15) K at atmospheric pressure. From these data, excess molar volume ( VE ) was calculated. Viscosities of trimethyl phosphate were also measured over a temperature range of (283. 15 to 373. 15) K and the data were fitted to the Andrade equation. The density data were fitted to a second-order polynomial. The excess molar volumes were fitted to the Redlich-Kister equation using a nonlinear regression method. Results show that the density and viscosity gradually decreases with the increase of temperature.