[en] A 33.3 MHz radio frequency cw power amplifier (P.A.) system has been installed in the Accelerator Lab. of ICR, Kyoto University. The system comprises of three major subsystems operating in the same frequency: a 50 kW P.A. for a RFQ linac, a 5 kW P.A. for a post accel./decelerator and a phase-shifting unit, which adjusts the phase relationship between the two P.A.s. The system is fully tested using dummy loads and is confirmed to satisfy our specification. This work is part of the continuing program for the development of a commercial heavy ion MeV RFQ linac. (author)