Provided is a method of synthesizing silver nanoparticles including: a) a nucleation step of reacting a composition containing a silver precursor, a heterogeneous metal precursor, and an amine-based compound at 30 to 120° C. to form a nucleus; and b) a growth step of reacting the composition containing the nucleus formed therein at 155 to 350° C. to grow the nucleus. According to the present invention, significantly uniform and fine silver nanoparticles may be synthesized with high reproducibility on a large scale.