Effects of mixing dye sensitizer for the photocatalytic activity of dye-sensitized Pt/K0.95Ta0.92Zr0.08O 3 was investigated. It was found that the photocatalytic activity was greatly improved by mixing dye sensitizer on the catalyst, and among the examined combination of organic dyes, the highest photocatalytic activity was obtained by mixing Cr-tetraphenylporphyrin (Cr-TPP) and Pentametylene bis[4-(10, 15, 20-triphenylporphine-5-yl)benzoate] dizinc(II) (Zn-TPP dimer). In order to identify the effect of dye sensitizer, photovoltaic behavior of the dye-sensitized KTaO3 was investigated. The lifetime of the photo-exited electron and hole can be improved by coating with dye sensitizer. Thus, the effect of porphyrinoids would be explained by the improved efficiency of charge separation.