Various acoustic parameters like isentropic compressibility (β_s) intermolecular free length (L_f), apparent molar volume (ø), apparent molar compressibility (ø_k), molar compressibility (w), molar sound velocity (R), acoustic impedance (Z) of KCl in 10%, 20%, 30% and dioxan and water solvent mixture at 303.15K have been determined from ultrasonic velocity (V), density (ρ) and relative viscosity (η_r) of the solution. These parameters are related with the molar concentration of the solution and reflects the distoration of the structure of the solvent in dioxan and water mixture when the solute is added to it.