Uniform Ag nanoparticles (< 10 nm) were effectively prepared in 1-amino-4-methylpiperazine as a solvent with multiple functions including reduction and stabilization. An Ag-complex such as $Ag_2(ehac)_2(eha)_2$ (ehac = 2-ethylhexylammonium carbamate; eha = 2-ethylhexylamine) was used as an Ag-precursor, whereas the usage of a salt such as $AgNO_3$ showed the formation of Ag nanoparticles in larger and irregular size (30 - 500 nm). The Ag nanoparticles (< 10 nm) prepared by using the Ag-complex could also be effectively stabilized by 1-amino-4-methylpiperazine. Transmission electron micrographs confirmed that the Ag particles were spherical and in the nanometer size.