A method of preparing a polymer-supported catalyst for hydrogen generation is introduced in this article. This polymer-supported catalyst is the structure of ruthenium (Ru) nano-particle immobilized on a monodisperse polystyrene (PSt) microsphere. The diameter of the Ru nanoparticle is around 16 nm, and the diameter of the PSt microsphere is 2.65 um. This preparation method is accomplished by two unique techniques: one is sodium lauryl sulfate/sodium formaldehyde sulfoxylate (SLS/SFS) interface-initiated system, the other is 2-methacrylic acid 3-(bis-carboxymethylamino)-2-hydroxy-propyl ester (GMA-IDA) chelating monomer. By taking advantage of these two techniques, Ru3+ ion will be chelated and then reduced to Ru-(0) nanoparticle over PSt surface predominantly. The hydrolysis of alkaline sodium borohydride (NaBH4) solution catalyzed by this Ru-immobilized polymer-supported catalyst is also examined in this article. It reveals that the hydrogen generation rate is 215.9 ml/min g-cat. in a diluted solution containing 1 wt.% NaBH4 and 1 wt.% NaOH, and this Ru-immobilized polymer-supported catalyst could be recycled during the reaction. Crown Copyright (C) 2009 Published by Elsevier Ltd on behalf of International Association for Hydrogen Energy. All rights reserved.