This paper evaluates the catalytic effectiveness of CuZnOx/γ-Al2O3 catalyst for the degradation of an azo dye, acid red GR, using H2O2 as an oxidant, under very mild conditions (atmospheric pressure and t = 40 ). In the catalytic wet peroxide oxidation (CWPO) process, the results show that it is possible to remove 80% of COD during the initial 30 h. But a considerable drop of catalytic activity is found after prolonged run. As characterization datas shown, the deactivation of the catalyst is caused by the depositon of intermediates on the surface and serious coverage of the active sites. However, calcination method which is possible to burn the organic species that trapped in the catalyst reaches complete restoration of the spent catalyst.