Abstract: Inorgano-organo- montmorillonites were obtained by using Keggin ion which prepared by reaction of Al³⁺and alkaline solution at the molar ratio of OH^-/Al³⁺=2.4.It was shown by XRD analysis that the dimension of the pillared interlayer montmorillonites obtained was increased to 1.9 nm and over.The adsorption of nitrobenzene on four modified montmorillonites was also studied and the results indicated that the adsorption capacities of inorgano-organo-montmorillonites were much better than Na-montmorillonites.The adsorption dynamics follows the laws of Bingham and Langmuir equation.The relation between adsorbtive capacity (q_e) and equilibrium concentration (C_e) fitted the isothermal adsorption equations of Freundlich and Langmuir.The adsorption could be interpreted as exothermic physical adsorption and organic compound partition.