Chua's circuit and its characteristics, as well as the circuit of realizing non-linearity resistance, are presented. Using Chua's circuit, a drive-response chaotic synchronization system is constructed, by means of imitation, it can be concluded that this synchronization system possesses a certainly stability, resisting-disturbance and so on. Based on its system and using imitation, the characteristic of chaos synchronization self-maintenance is put forward, and imitation results are presented, this discovery provides the foundation of putting chaos into practice application to secret communication.