Ultrasonic velocity,density and viscosity have been measured for citric acid in double distilled water at 298.15K,303.15K,308.15K,313.15K and 318.15K. Thermodynamic parameters such as adiabatic compressibility(β), acoustic impedance (z),intermolecular free length(Lf) and Relative association number (RA) have been obtained from the experimental data for all the solutions of citric acid with various concentrations and temperatures, with a view to investigate the exact nature of the molecular interaction. Adiabatic compressibility and intermolecular free length decreases with increase in concentration and temperature and gradually increases with concentration of solutes. These parameters have further used to interpret the hydrophilic part of the solute and molecular interactions in the solutions.