Abstract: Polyacrylonitrile (PAN) fiber was modified by hydrazine and hydroxylamine to enable ligation of ferric ions to the fiber surface so as to produce a Fe-modified PAN fibrous catalyst (PAN-Fe) for the oxidative degradation of two soluble anionic azo dyes in the presence of H2O2. The dosage of catalysts, ferric ion content loading on catalyst, dye concentration and pH values on the photocatalytic decoloration of two azo dyes in water were investigated in this paper. The results indicated that PAN-Fe catalyst has a significant catalytic property on oxidative degradation of two azo dyes, especially under light irradiation. Increasing the dosage of catalysts and enhancing ferric ion content lead to high decoloration level. Moreover, the decoloration of two azo dyes is developed in the presence of the catalysts under alkaline condition, but increasing concentration of dyes in solution causes the low decoloration percentage.