To provide a trunked system capable of testing a radio terminal device by switching the device to a test mode remotely from a base station device.

A trunked system includes: a base station device which generates an encrypted control data by encrypting a test control data having a test instruction described therein with an encryption key for releasing a test function, and arranges a key ID corresponding to the encryption key for releasing a test function, and the encrypted control data into a transmission frame, so as to transmit them to a radio terminal device; and a radio terminal device which decrypts the encrypted control data with the encryption key for releasing a test function corresponding to the key ID, to regenerate the test control data, and starts a test according to the test instruction described in the test control data.