Titania/surfactant composite particles with nanoscale ordered structure have been prepared by hydrolysis and condensation reactions of titanium oxysulfate in the presence of molecular assemblies formed at aqueous mixtures of cationic and anionic surfactants as structure-directing agents. When cetyltrimethylammonium bromide (CTAB) and sodium octylsulfate (SOS) were used as cationic and anionic surfactants, respectively, particles with hexagonal type ordered nanostructure were obtained at CTAB-rich compositions and their repetition unit increased with increasing SOS content, while the hexagonal structure changed to lamellar structure at a certain SOS content and the repetition unit decreased above this content. These results showed that precise control of geometry and size of the nanoscale-ordered structure is possible by manipulation of the compositions of cationic CTAB and anionic SOS.