A novel organically templated layered cerium phosphate-hydrogen sulfate [enH(2)](0.5)[Ce-III(PO4)(HSO4)(OH2)] has been hydrothermally synthesized. The product was further characterized by means of single-crystal and powder X-ray diffractions, TG-DTA, CHN elemental analysis, SEM, and IR. Its unique layered structure possesses cerium-centered polyhedral CeO9 as a new basic building unit. The diprotonated ethylenediamine cations contact adjacent layers via hydrogen bonds to compensate the charge of the inorganic framework.