The present invention relates to substances which can be applied to the technical fields of gas storages, polymerization catalysts and optical isomers, their intermediates, and processes for preparing the same, which is characterized in that 1) possible disintegration of structure of the scaffold material (SM) is impeded, and 2) they are prepared by a simple manufacturing system as compared to the substances conventionally suggested in the application field. Specifically, it relates to scaffold material-transition metal hydride complexes comprised of scaffold material (SM) and transition metal hydride (M1H(n-1)) which is chemically bonded to the functional groups formed on the scaffold material, SM-transition metal halide complex and SM-transition metal ligand complex as the precursors, and a process for preparing the same. The SM-transition metal hydride complex according to the present invention is a substance for hydrogen storage which adsorbs hydrogen via Kubas adsorption. The complex according to the invention can store high capacity of hydrogen with safety and reversibility, while disintegration of its structure does not occur even with repeated adsorption-desorption of hydrogen.