Abstract: Based on chaotic Genesio system, this paper proposes a method for constructing a generally synchronizing system. First, to transform transmitter system using scalar output function; Second, to construct receiver system; at last, to apply this method to private communication. In addition, Hurwitz stability theory ensures that the whole system is global stable. Numerical simulations show that the transmitter system and the receiver system, though they are different, are generally synchronized. Moreover, the hidden signal is recovered with high quality when they are applied to private communication.