The In₂S₃ nano-flower films on TiO₂/FTO (Fluorine-doped tin oxide) substrates were synthesized via hydrothermal method and the photoelectrochemical performances of In₂S₃/TiO₂ photoelectrodes were characterized. The roles of PSS (poly(sodium-p-styrenesul-fonate)) and PEG (polyethylene glycol) on the structure controlling of In₂S₃ films were also discussed. The results show that the In₂S₃ nano-flower films consisted of ultrathin nanoflakes with a thickness of 5 nm are successfully grew on the surface of TiO₂ nanorod arrays. PEG could play a role as the morphology-directing agent by confining crystal growth in certain directions, while PSS could provide coordination sites with long chains and lead to the formation of spherical structure. The energy conversion efficiency of In₂S₃ nano-flower/TiO₂ photoelectrodes enhances thrice compared with that of bare TiO₂ photoelectrode. This research presents further insight for improving the efficiency of semiconductors by using the suitable electron transfer channels, which may be promising for rational construction of solar conversion and storage devices.