Heterostructured BaTiO3/TiO2 composite nanofibers were fabricated by in situ hydrothermal method using TiO2 nanofibers as both template and reactant. The morphology and structure of BaTiO3/TiO2 composite nanofibers were characterized by X-ray diffiaction (XRD), scanning electron microscope (SEM) and high-resolution transmission electron microscope (HRTEM). Photocatalytic activity was tested via rhodamine B and phenol degradation as the model reaction. The results showed that the as-fabricated sample was composed of BaTiO3 nanoparticles assembling uniformly on the surface of TiO2 nanofibers to form BaTiO3/TiO2 heterostructures. Compared with the pure TiO2 nanofibers, BaTiO3/TiO2 composite nanofibers exhibited enhanced photocatalytic activity in the decomposition of rhodamine B under UV illumination. The degradation of both RB and phenol followed first-order reaction kinetics, and the composite showed higher photoactivity than did the pure anatase TiO2. The composite nanofibers also showed good catalytic stability and the decolorizing efficiency of RB solution remained as high as 96% after 5 times recycle. Moreover, the catalyst was easily separated and removed from the system after reaction and reuse.