Imidazolium-functionalized hyperbranched polymeric ionic liquids (HPILs) are synthesized by one-step reaction between tri-imidazolium-based ester (A(3) monomer) and dihaloalkane (B-2 monomer), which can act as efficient stabilizers in the preparation of silver nanoparticles. The particle size and solubility of nanoparticles mainly depend on the chemical structure of stabilizer, molecular weights of HPILs, and concentration of reagent. The obtained HPIL-encapsulated Ag nanoparticles were characterized by ultraviolet-visible (UV-Vis) absorption and transmission electron microscopy, showing a uniform size distribution and appreciable stability in water for a longer period. (C) 2016 Elsevier B.V. All rights reserved.