Based on the study result of cosmochemistry and Earth sciences, authors consider that Earth is accreted, in the narrow feeding zones of inner nebula, from silicate planetesimals by stochastic accretion processes. Before planetesimals formed, the early nebula had undergone vielent depletion of volatile elements, meanwhile, the fractionation of metal, sulfides and silicates had occurred also and fractionation was reinforced along with the processes of the formation of planets. In the Earth’s distinct accretion zones, mixing in the nebula is not complete and the chemical compositions among planetesimal groups is not homogenized, thus, the Earth was formed by a suit of Planetesimals which had independent chemical composition significance and were different from the meteorites o rtheir combinations found in the Earth until now.