A plasma/catalyst hybrid reactor was designed to overcome the limits of plasma and catalyst technologies. A two-plasma/catalyst hybrid system was used to decompose VOCs (toluene) and NOx at temperature lower than 150 ℃. The single-stage type (Plasma-driven catalyst process) is the system in which catalysts are installed in a nonthermal plasma reactor. And the two-stage type (Plasma-enhanced process) is the system in which a plasma and a catalyst reactor are connected in series. The catalysts prepared in this experiment were Pt/TiO2 and Pt/Al2O3 of powder type and Pd/ZrO2, Pt/ZrO2 and Pt/Al2O3 which were catalysts of honeycomb type. When a plasma-driven catalyst reactor with Pt/Al2O3 decomposed only toluene, it removed just more 20% than the only plasma reactor but the selectivity of CO2 was remarkably elevated as compared with only the plasma reactor. In case of decomposing VOCs (toluene) and NOx using plasma-enhanced catalyst reactor with Pt/ZrO2 or Pt/Al2O3, the conversion of toluene to CO2 was nearly 100% and about 80% of NOx was removed.