Chua’s circuits are non-smooth systems. At first,by the generalized Hamiltonian system and observer approach,the problem of the chaotic synchronization of Chua’s circuits with nonlinear control is transformed into that of the stability of zero solution of smooth error systems with nonlinear control. Then,the sliding mode control is applied to the error systems, which stabilizes their zero solutions,and the synchronization conditions are obtained. At last,the numerical results are shown to be in very good agreement with the theoretical analysis.