Abstract: The degradations reactions of soluble reactive brilliant red by hydrogen peroxide/ferrioxalate complexes were studied under the solar light.The influence of the pH,usage of hydrogen peroxide and ferric oxalate,light intensity,initial concentration of reactive brilliant red in solution reaction on photocatalysis were discussed.The results indicated that the initial pH of the solution,the usage of hydrogen peroxide and ferric oxalate,light intensity have significant effects on this photooxidative process.In the research scope,the degradation reaction of reactive brilliant red is the best by hydrogen peroxide/ferric oxalate under pH=3.0 and solar irradiation.And light intensity can accelerate the process of degradation effectively.The removal percentage of color and TOC by hydrogen peroxide/ferric oxalate is higher than UV/TiO₂.under different light intensity and different lamp.