We analyzed the effects of several process variables on removal efficiencies of NO and SO2 by the low temperature plasma process combined with photocatalysts. The cylinder-wire type, dielectric barrier discharge process for plasma generation was used. The photocatalysts were coated onto the glass beads by dip-coating method. As the voltage applied to the plasma reactor increases, or as the pulse frequency of applied voltage increases, the NO and SO2 removal efficiencies also increase. As the initial NO concentration decreases, or as the residence time increases, the NO and SO2 removal efficiencies increase.