Niobium oxide (Nb₂O<SUB>5</SUB>) has a strong chemical coherence and good electrical conductivity. Therefore, this material is helpful to enhance the performance of the dye sensitized solar cells (DSC) by improving the electron mobility. In this study, Nb₂O<SUB>5</SUB> was mixed with TiO₂ and this compound was applied to the DSC to improve its performance. As a result, the current density of the DSC using the Nb₂O<SUB>5</SUB>-TiO₂ compound on the photoelectrode was increased, because the internal resistance concerned to the electron transfer in the photoelectrode of DSC was decreased. However, large amount of the Nb₂O<SUB>5</SUB> induces the decrease of the efficiency of the DSC because the surface area to attach dye molecules is decreased due to the large particle of Nb₂O<SUB>5</SUB>. Therefore, it is important to optimize the mixture ratio of the Nb₂O<SUB>5</SUB>-TiO₂ compound for maximizing the performance of the DSC. Finally, the most optimum performance of the DSC was shown in case of the Nb₂O<SUB>5</SUB> concentration of 10 wt% of the Nb₂O<SUB>5</SUB>-TiO₂ compound.