Experiments on synthesis gas preparation from dry reforming of methane by carbon dioxide with thermal plasma only and cooperation of thermal plasma with commercial catalysts have been performed. in all experiments, nitrogen gas was used as the plasma gas to form a high-temperature jet injected into a tube reactor. A mixture of CH4 and CO2 was fed vertically into the jet. Both kinds of experiments were conducted in the same conditions, such as total flux of feed gases, the molar ratio of CH4/CO2, and the plasma power except with or without catalysts in the tube reactor. Higher conversion of CH4 and CO2, higher selectivity of H-2 and CO2 and higher specific energy of the process were achieved by thermal plasma with catalysts. For example, the conversions of CH4 and CO2 were high to 96.33% and 84.63%, and the selectivies of CO and H-2 were also high to 91.99% and 74.23%, respectively. Both were 10-20% higher than those by thermal plasma only. (C) 2008 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.