Hydrogen produced from CH4-O-2 reforming by an optimized rotating gliding arc discharge plasma reactor is investigated in this study. The effect of CH4/CO2 ratio (mole ratio), total input flow rate, discharge gap, voltage, and discharge frequency are analyzed. The results show that H-2 yield increases with the increase of CH4/CO2 ratio. Arc can be stretched effectively by increasing total input flow rate, then the discharge region is enlarged. Increasing discharge gap can enlarge the discharge region, but the reaction of the gas mixture would be suppressed if the discharge region was excessively large. The discharge region decreases with the increased discharge frequency to a certain degree. Based on the experimental results, the optimal experimental condition is concluded as applied voltage 60 V, discharge frequency 20 kHz, and minimum discharge gap 3 mm. It is anticipated that the results would serve as a good guideline to the application of hydrogen production from hydrocarbon fuels by plasma reforming onboard. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.