The present invention relates to a nanostructured metal powder and a method of fabricating the same. A twin-wire electric arc process is performed to melt the wire tips, and metal melt is formed. Simultaneously, the metal melt is broken up into melt droplets by an atomizing device. The operating temperature of the electric arc process is controlled between melting point and boiling point of the wire, to avoid vaporization of the melt droplets. Then, a fast cooling is performed to quench the melt droplets. Thus, melt droplets are solidified to nullm-scaled, spherical and dense powders comprising nano-grains (d