The ultrasonic velocity (u) and density (ρ) have been measured for ethyl acetate with 1-alkanols at 303.15K, over the entire range of composition. The thermodynamic parameter such as intermolecular free length (Lf), molar volume (V_m), isentropic compressibility (β_s) and internal pressure (P_i) have been obtained for all mixtures from experimental data with a view to investigating the exact nature of the molecular interaction. The excess values of the said parameter have also been calculated. The deviation from ideality of these parameters is explained on the basis of molecular interactions between the constituent components of the mixture.