Viscosity, density and ultrasonic velocity values have been measured experimentally in three binary liquid mixtures containing (quinoline+o-xylene),(quinoline+m-xylene) & (quinoline+p-xylene) at different temperatures at different mole fractions. These experimentally measured values have been used to obtain the excess Gibb’s free energy function (G*E) in all the three binary liquid mixtures at different temperatures. The obtained results have been used to explain the molecular interactions.