Abstract: The microstructure and functionality of nanocomposites were designed using mesoporous assembly. The mesoporous silica was loaded with metal nickel to obtain the nanocomposite through sol-gel method ( mixing and immersion route ) and sequent reduction treatment in hydrogen atmosphere. The nanocomposite was characterized by means of DSC, XRD, XPS, TEM, etc, indicating that the sizes of the nickel particles are dependent on the struc-ture and pore diameter of the mesoporous silica, and are affected by the reduction temperature and composition. The sizes of the nanoscale particles range from 8 to 20nm. The nanocomposites with uniform distribution were produced easily by using immersion. The surface of nickel nanoparticles oxidized because of the interlinked pore structure of silica, leading to a formation of shell structure of nanoparticles existing in the pores. The addition of rare-earth Ce increases the network strength for the host silica and restricts the aggregation and growth of the nanoparticles.