The control theory has wide application and is also important in physics teaching. Based on the formalism of Hamiltonian mechanics，the port-Hamiltonian framework provides a physics-based control strategy. This framework is also promising in teaching control theory in physics. In this paper，we employ the port - Hamiltonian framework to reformulate some classical physics systems and introduce the resulting physics - based control strategies，including the energy，dissipation and structure assignments. The closed-loop Hamiltonian is thus a candidate of Lyapunov function，which achieves the ( asymptotic) stability. The introduced physics-based control strategies are demonstrated using the Duffing oscillator and the Lorenz system. We also provide port-Hamiltonian descriptions for two examples in celestial mechanics.