In a network employing code division multiplex access, a distortion compensation amplifying apparatus is provided which is capable of making quick response to carry out the distortion compensation with high accuracy even if the signal power to be inputted thereto varies rapidly. In this distortion compensation amplifying apparatus, the renewal of a distortion compensation coefficient in a renewing unit is complemented on the basis of a result of amplification in an amplifier with respect to a signal code-division-multiplexed in a pseudo-signal multiplexing unit.