Nanostructures composited of vertical rutile TiO₂ nanorod arrays and Sb₂S₃ nanoparticles were prepared on an F:SnO₂ conductive glass by hydrothermal method and successive ionic layer adsorption and reaction method at low temperature. Sb₂S₃-sensitized TiO₂ nanorod solar cells were assembled using the SB₂S₃-TiO₂ nanostructure as the photoanode and a polysulfide solution as an electrolyte. Annealing effects on the optical and photovoltaic properties of SB₂S₃-TiO₂ nanostructure were studied systematically. As the annealing temperatures increased, a regular red shift of the bandgap of Sb₂S₃ nanoparticles was observed, where the bandgap decreased from 2.25 to 1.73 eV. At the same time, the photovoltaic conversion efficiency for the nanostructured solar cells increased from 0.46% up to 1.47% as a consequence of the annealing effect. This improvement can be explained by considering the changes in the morphology, the crystalline quality, and the optical properties caused by the annealing treatment.