A solution of Orange II, one of the typical azo dyestuffs was electrolyzed by Solid Polymer Electrolyte (SPE) electrolysis with two high oxygen overvoltage anodes, PbO₂ and SnO₂ without adding any electrolytes. The solution was decolorized completely by the 120 minutes electrolysis, using PbO₂ anode at current density of 0.2 A·:cm^-2. However, even after 180 minutes of electrolysis with PbO₂ anode at 0.3 A·cm^-2, 60% of total organic carbon (TOC) and 35% of chemical oxygen demand (COD) remained. Biodegradability of the electrolyzedobserved at high current density condition (about 0.5 A·cm^-2) and longterm electrolysis (about 200 hours). TOC reduction was higher for SnO₂ electrode doped with 1% Sb than for PbO₂. Although Sb doping reduced cell resistance, the electrolytical cell voltage for SnO₂ (8.5V) was much higher than that of PbO₂ (3.5V).