The characteristic features of the morphology and dynamics of binary mixture for substrate-directed spinodal decomposition (SDSD) in three dimensions have been Studied Using numerical simulations. The simulation results show that the formation of the wetting layer on the substrate interface follows the power-law growth. It is found that the Continuous influence of anisotropic diffusive behavior arose by wetting of substrate induces the wetting component spreading onto the interface of the substrate randomly. The phase morphology and averaged size in the vicinity of the substrate fluctuate greatly due to the wetting of the Substrate. The self-similar evolution of the cross-sections parallel and perpendicular to the Substrate interface is discussed by relevant scale law functions. respectively. And the mechanisms of the growth in both the parallel and perpendicular directions are also investigated. (c) 2005 Elsevier Ltd. All rights reserved.