The invention provides a method for preparing nano silver particles comprising mixing polyvinyl pyrrolidone (PVP) and silver nitrate (AgNO3) in a solvent to form a reactive solution, heating the reactive solution to a temperature less than the boiling point of the solvent for the formation reaction of nano silver particles, adding an accelerating agent into the reactive solution during the formation reaction of the nano silver particles, and terminating the formation reaction when the size of the nano silver particles formed in the reaction solution reaches about 50 nm to 120 nm in diameter.
