First, we present a new dynamical approach for measuring the temperature of a Hamiltonian systems in the microcanonical ensemble of thermodynamics. Then we study the temperature of quartic oscillator with two degrees of freedom and Henon Heiles oscillator. Finally, we study the temperature and specific heat per particle of a system of N fully coupled classical particles, which shows a second order phase transition. And we find that macroscopic variables such as temperature can be defined for chaotic systems with finite degree of freedom.
