The use of LFG is suggested as one of Greenhouse gas reduction plan and renewable energy research. In this study, we have studied ATR reaction system using plasma and catalytic reaction as a way to utilize LFG. This ATR reaction is a method of using the exothermic energy of the partial oxidation reaction for the dry reforming reaction. The experiment was performed according to O2/C ratio. As a result of the experiment, it was confirmed that the ATR reaction was performed, and the production cost of the syngas was 6.0 kJ/L at an O2/C ratio of 0.3. The proper ratio of external heat source to internal exothermic reaction should be considered important.