With a view to realizing a titanium oxide structure that has a large surface area and enables efficient transfer of ions and electrons by virtue of titanium oxide particles connected to one another, an object of the invention is to develop a material useful as an active material for dye-sensitized solar cells, and a process for producing the material; a porous titanium oxide composition and a process for producing the composition; and a photoelectric conversion element comprising the titanium oxide structure or porous titanium oxide composition.