A co-reduction reaction was proposed to synthesize nanocrystalline intermetallics Fe3Si and Ni3Al under benzene-thermal conditions, The reactions were carried out in an autoclave at 450 degrees C using FeCl3 and SiCl4 or NiCl2 and AlCl3 as reactants, respectively, and metal Na as a reductant. The prepared samples were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The possible formation process and the effective factors of nanocrystalline intermetallic Fe,Si were discussed.