Silver nano-particles have been synthesized by liquid phase reduction method and alcohol reduction process. Silver nano-particles of the size 30 ~ 40 nm were formed successfully by alcohol reduction process. The formation, structure, morphology and size of silver nano-particles have been studied using FE-SEM, TEM, XRD, UV-visible spectroscopy. In particular high dispersion stability of the synthesized silver nano-particles could be obtained by PVP binding. Antibacterial activity of Ag/PET master batch sample made from its nano-silver particles showed excellent antibacterial activity against S. aureus and E. coli.