Density (r), viscosity (h) and ultrasonic velocity (U) have been carried out in three binary liquid mixtures of dimethylformamide (DMF), N-methylacetamide and N,N-dimethyl acetamide in benzonitrile at 303, 308 and 313K The experimental data have been used to calculate the adiabatic compressibility (b), free volume (Vf), Gibb?s free energy (DG), Grunberg interaction parameter (d) and their excess values. The results of excess parameter can be discussed in the light of intermolecular interaction in the binary mixtures.