Solid state reaction and liquid state reaction were used in preparing ZnO .The result showed that the efficiency of decolorization is related to the pH value of dyes solution,irradiation time, as well as the intensity of irradiation. After irradiation with sun light for 3h,the decolorizing efficiency was up to 90% when the concentration of dyes was 20 mg/L, the amount of catalyst was 40 mg and the acidity was pH 6 in 50 mL dye solution.
