The noncatalytic direct reformation of jet fuel was studied in a supercritical water medium using a specially designed 400-mL Haynes 230 alloy tubular reactor. The kinetic experiments were conducted at 1042 K, 240.9 bar, and at the same water flow rate with varying water-to-fuel feed ratio. The principal reactions are reformation of jet fuel into hydrogen and carbon oxides and pyrolysis of hydrocarbon molecules into lighter molecules. The effluent gas contained H2, CO, CO2 and CH4, with small concentration of C2H6. This paper discusses the effects of the water-to-fuel ratio on the hydrogen conversion and the extent of pyrolysis reaction. The results provide vital information for the optimization of the novel reformation process.