Smooth and uniform Ag/AgO nanoshells (about 3–4 nm) on carboxylated polystyrene latex particles were prepared by electrostatic attraction between negatively charged –COO− on the surface of carboxylated polystyrene latex particles and positively charged Ag(NH3)2+ in the solution, and subsequent decomposition of the silver complex. The resultant nanoparticles were characterized with Fourier transform infrared, transmission electron microscopy, scanning electron microscopy, and x-ray diffraction. The effects of reducing agents, the amount of NaOH and temperature on the morphology of hybrid latex particles were discussed.