The ultrasonic velocity, density and viscosity have been measured for the binary mixtures of 1- propanol with toluene, benzene and cyclohexane at 3 03K The experimental data have been used to calculate the acoustical parameters namely adiab atic compressibility ( β ), free length (L f ), free volume (V f ), internal pressure ( π i ), acoustic impedance (Z) and molar volume (V m ). The excess values of some the above parameters are also evalua ted and presented. A weak molecular interaction between the component molecules is obse rved in the present investigation. Also, the additionof non-polar component with polar 1-propano l causes dissociation of its hydrogen bonded structure. A weak magnitude of molecular ass ociation is observed in 1-prpoanol- cyclohexane system .