Nonthermal plasma chemical decomposition of water was carried out with two different types of reactors such as ferroelectric packed-bed (FPR) and silent discharge (SDR) to explore the possibility of hydrogen generation in a flow reaction system. When FPR was used, the H-2 yield in this reaction reached 63% at 150 kJ L-1 of supplied specific energy density in N-2. On the other hand, the H-2 yield was much lower with SDR than with FPR under the same conditions.