Supercritical water oxidation (SCWO, P>221 bar, T>374 ℃) is a promising method for the decomposition of refractory organic compounds. In this study, the SCWO of Ethylenediaminetetraacetic acid (EDTA) was carried out in a tubular-type continusous reactor system with an H2O2 oxidant at 387-500 ℃, 250 bar and residence time (RT) of 15.9-88.9 s. The decomposition efficiencies increased with increasing temperature and oxidant amount, while it was inversely proportional to feed flow rate. The decomposition efficiency of 99.6% was obtained at 500 ℃, 250 bar, oxidant amount of 400% and residence time of 40.1 s. The effect of temperature on the decomposition efficiency was more significant than that of oxidant amount. In the case of the decomposition efficiency of 5,000 mg/L of EDTA (3,063 mg/L as CODCr), the decompostion of 99% or higher was obtained at the condition of over 40.1 s (RT) and 200 stoichiometric% of H O in the supercritical water of 500 ℃ and 250 bar.