In this paper the lowest order constrained variational (LOCV) method has been used for calculation of liquid along different isentropic paths employing the Aziz potential. Some thermodynamic properties such as energy per particle, pressure, temperature, chemical potential, velocity of sound, adiabatic index and compressibility for normal liquid have been calculated. Our results indicate that the sound velocity is always less than the velocity of light in vacuum (c) showing that all calculated equations of state obey the causality condition. Finally, our calculations show that the adiabatic index is not constant and its value depends on both density and entropy of the system.