A pulsed bipolar plasma-catalytic system was used to treat organic waste gases over perovskite catalysts. The characteristics of the catalyst impedances, plasma discharge, and in situ optical emission spectra were represented for describing the plasma and catalyst actions. Compared with the reaction without plasma, the temperature at 99% conversion of butanone oxidation over La0.7Sr0.3MnO3/mullite catalyst at SED of 3.340 kJ L-1 reduced from 320 to 198 degrees C for the reaction with plasma. The maximum residual amounts of toluene and butanone in ozone after plasma catalysis were 0.30 and 0.52 ppmv, respectively. No organic by-products were observed in the plasma-catalysis. A synergy factor in the terms of the temperature was defined for the synergistic catalysis. Plasma-dissociation and synergistic catalysis were integrated into the plasma-catalytic reaction to establish the theoretical formula of the reaction by introducing the synergy factor. The results demonstrate that this formula can successfully interpret the behaviors of plasma-catalysis. Graphic