To provide a radio packet communication system simply setting a channel even if installing a plurality of base stations or connecting a mobile station to other base stations.

The radio packet communication system is composed of: base stations (master stations) 1a, 1b connected to a wired sub-network 3a; mobile stations (slave stations) 2a, 2b making radio communication with the base station 1a; and mobile stations (slave stations) 2c, 2d making radio communication with the base station 1b. The base station 1a uses a channel Ch1 to make radio communication with the mobile stations 2a, 2b belonging to its own station and uses the channel Ch1 even when the mobile stations 2a, 2b make radio communication mutually. Similarly the base station 1b uses a channel Ch2 to make radio communication with the mobile stations 2c, 2d an d uses the channel Ch2 even when the mobile stations 2c, 2d make radio communication mutually. The mobile stations 2a, 2b and 2c, 2d and the base stations 1a, 1b can change and set the channels Ch1, Ch2 respectively.