Abstract: A radio-telephone system employing a manner of changing a channel and a privacy digital code and interstoring them between by wireless and a method of changing the privacy digital code. The radio-telephone system comprises a stationary apparatus 100 and a portable apparatus 200. The stationary apparatus 100 includes a base MPU 410 containing a ROM, a charging power supply and sensing circuit 450, a transmitting and receiving PLL circuit 420, a duplex radio transmitting and receiving unit 430, a line connecting circuit 460 and an antenna A. The portable apparatus 200 includes a hand MPU 610 containing a RAM, a transmitting and receiving PLL circuit 620, a duplex radio transmitting and receiving unit 630, a charging circuit 680 and an antenna A'. The method of changing the privacy digital code is performed by using the radio-telephone system. Therefore, in accordance with the present invention, the selection of the talk channel having no crosstalk by the system software is enabled.