A uranium oxide hydrate framework, [Ii(I-120)2]1[(IJ02)10010(OH)2][(1J04)(H20)2]} (U0F1), was synthesized hydrothermally using schoepite as a uranium precursor. The crystal sti-uctitre of IJOF1 was revealed with synchrotronsingle-crystal Xray diffraction and confirmed with transmission electron miscroscopy. The typical uranyl oxide hydroxide layers similar to those in fi-U308 are further connected via double-pentago3nali bipyramidal uranium polyhedra to form a tfiree-dimensiona1 (3D) framework structure with tetravalent uranium species inside the channels. The presence of mixed-valence uranium was investigated with a combination of X-ray absorption near-edge structure and dititise reflectance spectroscopy. Apart from the major hexavalent uranium, evidence for tetravalent uranium was also found, consistent with the bond valence sum calculations. The successful preparation of U0F1 as the first pure uranium oxide hydrate framework sheds light on the structural understanding of the alteration of UO2_, as either a mineral or spent nuclear fuel.