PURPOSE: To reduce a call loss at the dialing in a radio telephone system.

CONSTITUTION: The position of a radio telephone set 16 is registered to the radio base station 13 of a radio zone 17, and when the radio telephone set 16 moves to a radio zone 19 in the case that both incoming and outgoing calls are available, a radio base station 15 having a strongest reception electric field of an informing signal among informing signals from a receptible radio base station is selected and a call signal is sent therethrough, then the radio base station 15 returns a call reply to establish the calling. Furthermore, a 1st calling is implemented to the base station 13 where the position of the telephone set is registered and when it is failed, the telephone set calls the base station 15, then the radio telephone set 16 in use is confirmed to be not present on the radio zone 17 and when the telephone set 16 stays within the radio zone 17, the erroneous updation of the position registration is prevented.