Plasma-catalytic conversion of CO2 and H2O into energy gases at room temperature was studied in a dielectric barrier discharge reactor. CO, H-2 , and traces of CH4 were observed as the products in an argon atmosphere. Moreover, NiO with different morphologies was prepared and loaded on cordierite as catalysts. Compared with NiO-grain and NiO-sheet, NiO-sphere showed higher catalytic performance; the yields of H-2, CO, and CH4 were 354.3, 21.0, and 0.061 mu mol.h(-1).g(cat)(-1), respectively. Characterization indicated that highly dispersed NiO nano- clusters, chemical adsorption of CO2, and defect formation may be the factors that promoted the catalytic performance. Subsequently, a kinetic analysis was performed for further understanding the reaction process.