Abstract: There is growing interest in applying supercritical water oxidation (SCWO) to the treatment of wastewaters arid sludgest As the typical representation of alcohols wastewater ethanol was selected and its oxidation in supercritical water was investigated. The experiments were performed in an isothermal, plug-flow reactor at temperatures from 748.2 to 823.2K, pressures from 22 to 30 MPa, reactor residence times from 0.6 to 63.7s, and oxygen/ethanol molar feed ratios from 4.56 to 9.09. The oxidation of ethanol was fast in supercritical water At temperature of 823.2K, pressure of 25MPa and residence time of more than 10s, the reaction conversion of ethanol to carbon dioxide was near 100 percent. Monoxide was the major intermediate of the process. The ethanol conversion increased with increasing residence time and temperature and did not obviously change with varying pressure or oxygen concentration.