The thermodynamic parameters and excess molar volumes have been calculated from the experimental value of densities and viscosities of binary mixtures of propyl acetate with pentan-1-ol at ( 298.15, 303.15, 308.15 and 313.15 ) K. All the mixtures exhibited endothermic enthalpies which decreased with increasing concentration of propyl acetate . The variations of the excess molar volumes and thermodynamic properties of these mixtures with concentration of propyl acetate and alkan-1-ol, These effects have been interpreted on the basis of molecular interactions. The excess molar volumes are fitted to Redlich - Kister equation. excess properties considered, and yielded acceptable results.