Because of the fundamental nature of condensed rare gases　their potentials and e quations of state have been studied extensively in recent years.In the present w ork　based on ab initio calculations on many－body interactions　the MSVⅢ potenti al proposed by Parson et al.for argon system has been modified　and the molec ula r dynamics method is employed to calculate the Hugoniot curve for liquid argon s ystem.Comparisons are performed between theoretical Hugoniot curve and the exper imental measurements.This demonstrates that the coincidence degree between the t heoretical and the experimental results is significantly improved.