A simple methodology to synthesize uniform and nano-sized Pd particles supported on silica support has been developed by the electroless deposition technique using Sn 2+ ion, in which Pd precursor can be interacted directly with the Sn 2+ ion, and subsequently transformed into Pd nanoparticles. Characterization by TEM analysis proved that the sizes of the Pd nanoparticles using the electroless deposition technique (eld-Pd/SiO 2 (Sn)) were quite uniform with smaller size compared with that prepared by the conventional impregnation method (imp-Pd/SiO 2 ). Their catalytic applications for the hydrogenation of nitrobenzene and the direct synthesis of H 2 O 2 from H 2 and O 2 gases were investigated and it is demonstrated that eld-Pd/SiO 2 (Sn) prepared by the electroless deposition technique was shown to perform significantly better activity than the imp-Pd/SiO 2 owing to its uniform and nano-sized Pd particles.