Experimental densities, viscosities and heat capacities at different temperatures were presented over the entire range of mole fraction for the binary mixture. of p-xylene and acetic acid. Density values were used in the determination of excess molar volumes, V-E. At the same time, the excess viscosity and excess molar heat capacities were calculated. The values of V-E, eta(E) and c(p)(E) were fitted to the Redlich-Kister equation. Good agreements were observed. The excess molar volumes are positive with a large maximum value located in the central concentration range. The excess viscosity has an opposite trend to the excess molar volume V-E. eta(E) values are negative over the entire range of the mixture. The cure of dependence of c(p)(E) on concentration has a special shape. The molecular interaction between p-xylene and acetic acid is discussed.