Considering the inevitable high energy input to implement the CO(2) reforming of methane under high-temperature operation using conventional catalysis method, the low temperature conversion of CO(2) and methane in the coaxial dielectric barrier discharge (DBD) plasma reactor was investigated in this work. Steam was introduced to enhance the CO(2) reforming of methane with synergetic catalysis effect by cold plasma and catalyst. The experimental results showed that a certain percent of steam could promote the conversion of both CH(4) and CO(2). Meanwhile, the carbon deposition was evidently reduced compared with the dry reforming of methane. With the increase of steam input, the steam reforming occurred predominantly. As a result, the hydrogen volume percentage in the product gases increased. In this way, the products with different H(2)/CO ratio could be achieved by changing the mole ratio of CH(4)/CO(2)/H(2)O at the reactor inlet. In particular, when the mole ratio of H(2)O/CH(4) increased to almost 3 corresponding to the pure steam reforming process, the conversion of CH(4) reached almost 0.95 and the selectivity to H(2) was almost 0.99 at 773K. Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.