A new route for synthesis of CNTs (Carbon Nano Tubes) was investigated by RF thermal plasma decomposition of methane injected with metal-oxide catalyst. From the FE-SEM images of the as-synthesized samples, it was found that multi-walled carbon nanotubes are mainly synthesized on the surface of the quartz guide, which is employed for expanding and confining RF thermal plasma flow issuing out of the RF torch exit. The lengths and the purity of as-synthesized CNTs were estimated to reach several tens ㎛ and ~70%, respectively. Little of CNTs, however, were observed in the as-synthesized samples retrieved from various positions, such as, quenching chamber and filtration. These experimental results show that CNTs can be continuously synthesized in the reaction zone specified by a reactor coupled with RF torch. For the formation of raction zone, carbon species and the catalyst particles were supplied continuously by RF thermal plasma decomposition of methane and its surface temperatures were also controlled by quenching gas flow rates in a reactor.