An organic-inorganic hybrid Langmuir-Blodgett(LB) film was produced through stabilization of a polyoxometalate (POM) monolayer by attaching electrostatically hydrophobic amine (DMDA). The surface pressure-area isotherm of POM-DMDA monolayer showed the stability against surface pressure up to 30 mN/m. The tendency of crystallization on water surface could be directly confirmed by the Brewster angle microscopy. The AFM images showed the aggregated particles of POM-DMDA. The XPS spectra indicated the presence of POM in the LB film and the molecular ratio of DMDA and POM was over 4.0. The XRD spectra showed POMs are positioned to two-dimensionally spread multilayer film..