The TiO2-B nanobelt (NB)/anatase TiO2 nanoparticle (NP) heterophase nanostructure is fabricated via layer-by-layer assembly. The heterophase nanostructure composition (i.e. the nanobelt-to-nanoparticle ratio) can be tuned conveniently by controlling the experimental conditions of the layer-by-layer assembly. The formation of heterophase junction is good for the separation of photogenerated electrons and holes. So, the heterophase nanostructures have been used to fabricate photoelectrode for high-efficiency dye-sensitized solar cells (DSSCs), which combines the advantages of the rapid electron transport in NBs and the high surface area of NPs. It is found that, with the optimum preparation conditions, DSSCs with heterophase composite photoelectrode show better photoelectric conversion efficiency (7.54%) than that either with the naked NB photoelectrode or the mechanical mixing NB-NP photoelectrode. It is elucidated by the photoelectron-injection drive force and the interfacial electron transport of DSSCs, which are characterized quantitatively, using the surface photovoltage spectra and electrochemical impedance spectra. The DSSC with optimal NB/NP ratio displays the larger photoelectron injection drive force and the fastest interfacial electron transfer. (C) 2012 Elsevier Ltd. All rights reserved.