In order to achieve high energy conversion efficiency of the ruthenium-dye (Dye 1)-sensitized TiO2 solar cells, it is required to control each interface among meso-porous-TiO2 film as an electron transport layer, dye molecules as a charge carrier generator, and I-/I3-redox solution as a hole transport layer. This review article deals with our researches on the electronic control of the interface structures of the dye-sensitized solar cells.