We present a molecular dynamics method based on the Gauss’ principle of least constraint to calculate the shock polar of various liquids. Comparison of numerical results obtained from Gauss mechanics and Newton mechanics (this last case corresponding to the propagation of a real shock wave in the sample) shows that the two methods give the same final thermodynamic state. However, Gauss mechanics is interesting because the equilibrium state is reached very quickly (about10−13&hthinsp;s) and not many particles (a few thousand) are required for the simulation. Then, Gauss mechanics appears to be a very efficient method to evaluate a thermodynamic state obeying particular relation, such as Hugoniot, in a systematic way. Simulations on liquid argon and nitromethane are presented. ©2000 American Institute of Physics.