The present invention relates to a method for producing metal nanoparticles and metal nanoparticles produced thereby, in particular, to a method for producing metal nanoparticles used for inkjet that comprises, preparing metal nanoparticles capped with a fatty acid; heating a mixture of the capped metal nanoparticles and a linear or branched first amine of C1-C7 so that a part of the fatty acid is substituted to the first amine; and heating after adding a linear or branched second amine of C.sub.8-C.sub.20 to the mixture so that the first amine is re-substituted to the second amine. According to the present invention, metal nanoparticles capped with 2 kinds of dispersants can be produced massively, and its application to ink for inkjet technique can lower the curing temperature of ink.