We report the synthesis and structure characterization of a new family of lanthanide-based inorganic-organic hybrid frameworks, Ln(2)(OH)(4)[O3S(CH2)(n)SO3]center dot 2H(2)O (Ln = La, Ce, Pr, Nd, Sm; n = 3, 4), and their oxide derivatives. Highly crystallized samples were synthesized by homogeneous precipitation of Ln(3+) ions from a solution containing alpha,omega-organodisulfonate salts promoted by slow hydrolysis of hexamethylenetetramine. The crystal structure solved from powder X-ray diffraction data revealed that this material comprises two-dimensional cationic lanthanide hydroxide {[Ln(OH)(2)(H2O)](+)}(infinity) layers, which are cross-linked by alpha,omega-organodisulfonate ligands into a three-dimensional pillared framework. This hybrid framework can be regarded as a derivative of UCl3-type Ln(OH)(3) involving penetration of organic chains into two {LnO(9)} polyhedra. Substitutional modification of the lanthanide coordination promotes a 2D arrangement of the {LnO(9)} polyhedra. A new hybrid oxide, Ln(2)O(2)[O3S(CH2)(n)SO3], which is supposed to consist of alternating {[Ln(2)O(2)](2+)}(infinity) layers and alpha,omega-organodisulfonate ligands, can be derived from the hydroxide form upon dehydration/dehydroxylation. These hybrid frameworks provide new opportunities to engineer the interlayer chemistry of layered structures and achieve advanced functionalities coupled with the advantages of lanthanide elements.