The narrow-dispersed dendrimer-encapsulated gold nanoparticles without agglomeration were prepared from the grafted-dendrimers on the surface of the silica microspheres, successively by complexation of the gold chloride anion with the nitrogen atom of the dendrimer and the reduction with sodium borohydride as reductant. The hollow capsule-stabilized gold nanoparticles were prepared through the encapsulation of dendrimer successively by LBL self-assembly process of polyelectrolytes with modified-silica as template and removal of the silica core by hydrofluoric acid. The size of gold nanoparticles was 2.3 +/- 0.8 nm. The catalytic activity of the capsule-stabilized gold nanoparticles was investigated in the reduction reaction of 4-nitrophenol to 4-aminophenol with sodium borohydride as reductant. (c) 2006 Elsevier Inc. All rights reserved.