A radio data communications method capable of changing control points located in a network without causing loss of data when a mobile terminal is performing a soft handover. In the radio data communications method in which at least one of a first radio network controller and a second radio network controller performs a soft handover process for allowing a soft handover of a mobile terminal when the mobile terminal is performing soft handover, in downlink radio data communications in which the first radio network controller transmits data to a mobile terminal via a second radio network controller and a base station (or in uplink radio data communications). The first radio network controller or the second radio network controller performing the soft handover process is changed when the mobile terminal is performing the soft handover.