TiO 2 nanoribbons were synthesized hydrothermally via the reaction of TiO 2 particles and NaOH solution. Their photovoltaic properties were studied by surface photovoltage spectroscopy (SPS) and electric field-induced surface photovoltage spectroscopy (FISPS). Under the external field, new photovoltaic response bands were found from 375 nm to 550 nm. It is suggested that these response bands resulted from the surface states, which can be ascribed to the formation of steps and kinks in the TiO 2 nanoribbons.