Water-soluble starlike polymers containing concentrated carboxyl groups were conveniently synthesized via the combination of "click" chemistry and atom transfer radical polymerization. The starlike polymer was composed of a shorter polyacrylate main chain and longer poly(acrylic acid) side chains. Alkyne and azide groups were introduced to the structure units of the main chain by esterification and the chain end of the side chain by substitution reaction of NaN3 to bromine, respectively. By click chemistry between alkyne and azide group, well-defined starlike polymers were obtained. FT-IR, gel permeation chromatography, and H-1 NMR were used to characterize the resulting polymers. Aggregation behavior demonstrated by transmission electron microscopy was observed when the starlike polymers were dispersed in water at pH 7.0-7.5. Using the starlike polymers as templates, water-soluble silver nanoclusters mainly consisting of Ag-2 supported by the generated nanoparticles and carboxyl groups were successfully synthesized. Also, their optical properties and morphology were characterized by UV-vis absorption spectra and TEM.