The experimental densities p and sound velocities u for binary mixtures of TBP-dodecane have been measured at temperatures from 298.15 to 323.15K and atmospheric pressure over the whole mole fraction range. From these data, the excess molar volume (V^E) and deviation in isentropic compressibility (Ak_s) have been calculated and fitted to Redlich-Kister polynomial equation. VE and Aks values are positive for TBP-dodecane over the whole mole fraction range and at the above-mentioned temperatures. Excess thermal expansion coefficients (α^E) of a mixture of equimolar composition and deviations in molar volume of the components at infinite dilution have been calculated at all temperatures. The variations of these properties with composition and temperature of the binary mixture are discussed in terms of molecular interactions.