Abstract: In order to investigate the visible light photocatalytic properties of Mn-N co-doped TiO₂ loaded bamboo based activated carbon fibers (Mn-N/TiO₂-BACF), using MnSO₄·H₂O as manganese source and urea as nitrogen source, photocatalytic composites Mn-N/TiO₂-BACF were prepared by sol-gel method firstly. Then, the effects of calcination temperature on the structure and visible light photocatalytic properties of Mn-N/TiO₂-BACF were investigated by SEM, XRD and XPS etc. The results indicate that the photoresponse edge of photocatalytic composites extends from ultraviolet light region to visible light region upon Mn-N co-doping. With increasing calcination temperature, the lattice oxygen content on the surfaces of photocatalytic composites decrease gradually, absorbed oxygen content decreases firstly and then increases, while hydroxyl oxygen content increases. After illuminating for 400 min, the photodegradation ratio for methylene blue of Mn-N/TiO₂-BACF prepared by calcined at 350℃ reaches 99.7% under visible light. Moreover, it is also found that the photodegradation rate of Mn-N/TiO₂-BACF under visible light has no correlation with calcination temperature.