We propose a novel scheme for controlling the nanostructures of organic polymer materials by using nanoparticles as templates and we also demonstrate a spontaneous fort-nation of arranged microdomain structures in block copolymers controlled by clay silicate layers dispersed at the nanometer level. Block copolymer-layered silicate nanocomposites were prepared by melt compounding of hydrogenated styrene-butadiene-styrene triblock copolymer with organophilic layered silicates intercalated with stearylammonium. Their morphologies were observed by transmission electron microscopy. The triblock copolymer microdomain structures were found to be arranged along the dispersed silicate layers. Such structures did not exist in the original block copolymer. TEM images suggest that the formation of the arranged microdomain structures are induced and controlled by the interaction of the silicate layers, which act as templates. It is thought that these controlled nanostructures were formed through the selective absorption of the polystyrene segments on dispersed silicate surfaces followed by segregation of each segment.