In this paper, we build a mathematic model of hop-parameter chaotic synchronization, propose and prove its sufficient condition, then analyze theoretically the condition for its realization. An efficient algorithm is proposed for about the hop-parameter chaotic synchronization and hop-parameter period synchronization. Based on the Chua's system, we have simulated the hop-parameter chaotic synchronization and its secure communication. Finally, the counteraction between the hop-parameter chaotic communication system and the wiretapping system is discussed. The simulation shows the hop-parameter chaotic synchronization and its secure communication have the virtue of easy realization and good security.