Simultaneous process of the production of spherical Ni powder and its surface-modification with Fe ultra-fine particles was demonstrated using an Ar RF plasma. In a reactor chamber, Fe raw powder introduced into the plasma flame was vaporized then condensed into Fe ultra-fine particles, while Ni raw powder introduced below the flame was melted then formed into spherical powder. Reaction characteristics of the Ni and Fe powders were investigated by varying the Ni/Fe supply ratio and the position of a counter-nozzle, which provided Ni powder, from the tip of the plasma flame. SEM observation and EDX analysis showed the spherical Ni powder is surface-modified with Fe ultra-fine particles.