Disclosed are amorphous carbon nanofibers including copper nanoparticles or copper alloy nanoparticles, copper composite nanoparticles prepared by grinding the amorphous carbon nanofibers and implemented as surfaces of Cu-included particles are partially or wholly coated with amorphous carbons, a dispersed solution including the copper composite nanoparticles, and preparation methods thereof and the amorphous carbon nanofibers include nanoparticles including copper, copper nanoparticles or copper alloy nanoparticles, and, the copper composite nanoparticles are implemented as surfaces of Cu-included particles are partially or wholly coated with amorphous carbons.