To improve its visible response capability and performance in cathode protection, ZnFe₂O_4doped TiO_2thin films have been successfully formed on glass and stainless steel substrates by liquid phase deposition (LPD) and in-situ hydrothermal conversion and crystallization in the Zn²⁺-contained environment afterwards. X-ray diffraction, electron microscopy (SEM) and field-emission scanning electron microscopy(FE-SEM)are used to study the crystal phases and shapes of layers. UV-visible spectrophotometry (UV-vis) indicates the aborting edge is shifted to visible light scale. The polarization curve shows the photovoltaic potential of ZnFe₂O_4doped TiO_2is more negative than the corrosion potential of bare stainless steel.