Fe 3 O 4 coatings were successfully fabricated on polyelectrolyte multilayered films by aqueous solution process using Pd catalyst nanoparticles. Fe 3 O 4 particles were selectively deposited on Pd catalysts which were adsorbed to the –NH 2 -terminated surface of polyelectrolytes, in an aqueous solution containing iron nitrate and dimethylamine-borane. Pd colloid catalyst particles were adhered to the amino group of the outmost layer of polyelectrolyte multilayered films mainly by electrostatic interaction. Crystalline Fe 3 O 4 particulate films were then deposited on the NH 2 -groups region by the effect of metal Pd catalyst. In addition, the surface charge density played an important role for adsorption behavior of Pd catalyst particles and Fe 3 O 4 film formation.