In summary, a free-standing CNTs/TiO2 nanofiber membrane was directly produced through the introduction of CNTs into the reaction system for preparing titanate nanofibers. We propose that the CNTs work as linkers between the nanofibers, and are crucial for forming the membrane under hydrothermal conditions. This strategy may be applied for making other carbon nanotube-based composite nano-fiber membranes. The as-prepared CNTs/TiO2 nanofiber membranes exhibit higher photocatalytic activity than pure TiO2 nanofibers towards photo-decomposing MB in waste water.