Due to the abundance of natural gas in the world, many studies have carried out to convert to C2 hydrocarbons. The purpose of this study is to develope a catalyst and to find a optimum reaction condition in which methane can be converted to C2 hydrocarbons. This experiment which methane can be converted to C2 hydrocarbons at the pressure of 5 to 10 torr and incident power changing from 300 to 600 Watt was carried out over Pd-Ni catalyst in the R.F. plasma system. Selectivity for ethylene was as high as 25%, for ethane 34% and for acetylene 43% Conversion of methane was as high as about 71% with pressure 6 - 10torr, total flow rate of 62.5ml/min and methane /oxygen ratio of 4:1 over Pd-Ni. This is suggested that the catalyst may provide sites for combination of radicals. Comparing to reported the others method, this study is showed that C2 yield and selectivity are increased.