This paper is concerned with the prediction and calculation of thermodynamic properties for binary and ternary mixtures of n-alkanes. An experimental database was established for this purpose, the database consists of density and dynamic viscosity for n-alkanes. Densities and dynamic viscosities measured were used to calculate the excess molar volumes, deviation in viscosities and excess free energies for the binary and ternary systems of (n-decane + n-heptane, n-decane + n-nonane, n-nonane + n-heptane and n-decane + n-nonane + n-heptane) over the entire range of volume fraction at temperatures from 293.15 K up to 343.15 K and atmospheric pressure. For all of the binary and ternary mixtures the computed excess molar volumes were correlated by applying the Redlich–Kister equation. and Prigogine–Flory–Patterson (PFP) theory. Many works carried out to predict the excess thermodynamic properties, but the mixtures of this work have not been studied so far at such conditions. It is hoped that the present work will help in the availability of experimental data for some unknown mixtures to understand their behavior in the chemical process, petrochemical industries and design processes. Excess molar volume and excess free energy are found to be positive for all binary and ternary mixtures at various temperatures, while the deviation in viscosities is negative. The obtained results are found to be in good agreement in their behavior as those given in the literatures....................... Keywords:................ Correlations, Excess properties, Density, Viscosity, n-heptane, n-nonane, n-decane, Binary and Ternary mixtures.