A RF excited CW CO2 waveguide laser has been developed, and effective match between the laser head and the RF power supply achieved. The exciting frequency was 35.8 MHz The discharge channel size was 2mm×2mm×150mm. The power output of up to 2.8 W and the efficiency of up to 4.8% have been obtained at a total pressure of 130 Torr with gas mixture ratio of CO2: N2: He: Xe=1:0.3:4.2:0.2.