Various acoustic parameters like isentropic compressibility (bs) intermolecular free length (L_f) apparent molar volume (f), apparent molar compressibility (f_k), molar compressibility (w), molar sound velocity (R), acoustic impedance (z) of KCl in 10%, 20%, 30% and dioxan+water at 303.15K have been determined from ultrasonic velocity (V), density (r) and relative viscosity (hr) of the solution. These parameters are related with the molar concentration of the solution and reflects the distortion of the structure of the solvent (i.e. dioxan + water) when the solute is added to it.