In solution the study of propagation of ultrasonic waves is useful for analyzing certain physical parameters. Science and technology of ultrasonic is widely used in recent years for industrial and medicinal application .Dichlofenac Sodium is a potent non steroidal anti inflammatory drug widely used in pharmaceutical because of its antiinflammatory analgesic and antipyretic effect. Physiochemical behavior and molecular interaction occurring in the aqueous solution of Dichlofenac Sodium can be studied with the help of ultrasonic velocity. Speed sound measurement has been done by multifrequency ultrasonic interferometer at 2MHZ frequency. From the values of ultrasonic velocity, density, viscosity the thermodynamic parameters such as free volume, Wada’s constant evaluated. The results have been interpreted in terms of solute solvent interaction.