Abstract: The efficiency and kinetics of the destruction of nitrogen - containing organic compounds in waste water by Supercritical Water Oxidation at 673. 2 K-823.2K and 24 MPa-30 MPa was investigated. The removal efficiencies are lower than 10% below 673.2K, and higher than 90% above 823.2 K. The increasing of the temperature, pressure or reaction time will result in the higher removal efficiency. Under the conditions of the experiments, the rate of removal of Kjeldahls Nitrogen is first order,and independent of the concentration of oxygen. The effect of temperature on the rate constant can be expressed by Arrherrius equation. The rate constant depends on the pressure especially near the critical point of water.