Abstract: It seems reasonable to assume the mechanism of metal-silicate separation between the initial cores and mantles of terrestrial planets during their thermal evolution process as thermal diffusion of Pe-Ni metals in solid state, partial melting of metals and metal-sulfides, and full melting and differentiation of metals, metal-sulfides and silicates. As a result of such metal-silicate redistribution, a small amount of silicate within the initial cores would move to the silicate mantles, and the metal-sulf ide components within the initial rock mantles would gradually sink to the cores, thus forming the final core-mantle struture patterns of terrestrial planets.