This study presents an approach to prepare nano-sized silver particles via in-situ reduction process. First, a reversible addition fragmentation chain transfer (RAFT) agent, 2-(dodecylthiocarbonothioylthio)propanoic acid (DTPA), was synthesized and characterized. Acrylic acid (AA) was polymerized in the presence of DTPA to afford an amphiphilic macro RAFT agent (DTPA-AC-10) with a calculated average degree of polymerization of ten. Latex particles with a sodium salt-containing shell were prepared by using sodium DTPA-AC-10 as a reactive surfactant. Then, through silver ion-exchange processs of the latex particles, the latex particles with silver salt at the surface were obtained. Finally, the silver salt at the particle surface was reduced through chemical reduction to give the silver-coated polymer particles. Dynamic Laser Scattering (DLS) was used to measure the particle size and distribution; X ray diffraction analysis (XRD) was employed to characterize the formed silver crystal in the particle surface. The diameter of the silver particles was about 76 nm and was narrowly distributed. The silver nanoparticles might be used to prepare conductive ink for ink-jet applications.