A general and straightforward way of preparing few-nanometer-sized well-separated MAPbI(x)Br(3-x) (MA=methylammonium) perovskite photosensitizers on the surface of an approximately 1 mu m thick mesoporous TiO2 photoanode was suggested through a two-step sequential deposition of low-concentrated lead halides (0.10-0.30 m PbI2 or PbBr2) and methylammonium iodide/bromide (MAI/MABr). When those nanoscale MAPbI(x)Br(3-x) perovskites were incorporated as a photosensitizer in typical solid-state dye-sensitized solar cells (ss-DSSCs), it could be verified clearly by the capacitance analysis that nano-particulate MAPbI(3) perovskites play the same role as that of a typical dye sensitizer (MK-2 molecule) although their size, composition, and structure are different.