Synchronization of chaotic system and its application to secure communication have received a great deal of attention in recent years.During the past studies on synchronization of chaotic system,identical synchronization,phase synchronization,generalized synchronization and projective synchronization had been proposed and achieved.In this talk,I would like to propose a new scenario of synchronization.As a generalization of the concept of generalized synchronization,this approach of synchronization can make all variables of drive system and response system reach proportional synchronization.It is different from projective synchronization in which only a part of corresponding variables can reach proportional synchronization for response system and drive system.