Abstract: A series of TiO₂/Bi₂O₃ heterojunction micro bers have been fabricated using cotton bers as bio-templates, and characterized by XRD, SEM and UV-Vis techniques. Results reveal that Bi₂O₃ in the TiO₂/Bi₂O₃ sample is assigned to monoclinic and tetragonal mix-crystal phase. Fibers lengths can reach several micrometers and diameters range from 0.5μm to 3μm. Compared with pure TiO₂ and Bi₂O₃, TiO₂/Bi₂O₃ samples display better absorption in visible light region. Photocatalytic activity was evaluated by degradation of MB under visible light irradiation. TiO₂/Bi₂O₃ micro bers exhibite much higher activity than pureTiO₂ and Bi₂O₃, and 22.84%TiO₂/Bi₂O₃ can achieve the decomposition of about 95%MB, which is attributed to synergistic e ects of the strong visible-light absorption of TiO₂/Bi₂O₃ micro bers and the heterojunction formed between TiO₂ and Bi₂O₃.