Heterostructured TiO2/Fe2O3 composite film was obtained by spin-coating alpha-Fe2O3 hydrosol on the TiO2 nanoparticulate film prepared by the soi-gel method. The composite film was characterized by surface photovoltaic spectroscopy (SPS) and electric-field-induced surface photovoltaic spectroscopy (EFSPS), and the results showed that the composite film had the extended photovoltaic response which can be modified by the external electric field. Based on these results, a photoinduced interfacial charge transfer mechanism was deduced and the energy band structure of the composite film was concluded.