In this study, crystal silver nanoparticle clusters, prepared by the reduction of AgNO3 in the presence of third-to-sixth-generation dendrimers with a trimesyl core, were characterized with ultraviolet-visible spectroscopy, transmission electron microscopy, and energy-dispersive X-ray spectroscopy. The results showed that the particle size of the silver nanoparticles was considerably affected by the generation of the dendrimers as well as the dendrimer concentration. When the concentration ratios of Ag+ to the third-to-sixth-generation dendrimers were all 4 : 1, the average diameters of the obtained particles were 6.7, 6.0, 5.2, and 4.3 nm, respectively. The data from high-resolution transmission electron microscopy and electron diffraction indicated that the particles belonged to a simple cubic crystal structure. (C) 2008 Wiley Periodicals, Inc.