Organic-Inorganic nanocomposites were prepared with Core-Shell Structure in two steps. In a first step the latex particles in the semibatch emulsion polymerization of butyl methacrylate (BMA) in the presence of methacrylic acid (MAA) were prepared. Small amounts of acrylic acid were incorporated into the latex to have better interaction between the surface of particles and inorganic phase. MAA also increase the latex stability and decrease the amount of coagulum. In a second step the Core-Shell structure have been prepared by the coating the latex particles with inorganic material. The core particles were encapsulated in a thin layer of silica by precipitation from a supersaturated sodium silicate solution at the pH range 10-12, and then Tetraethyl ortosilicate (TEOS) were hydrolyzed in presence of encapsulated core particles via sol-gel process to the growth of silica layer. Macroporous silica containing three-dimensionally connected voids, have been prepared by an elegant method. In this method the organic components were removed by combustion at 600degreesC. This method also showed core-shell structure of these organic-inorganic materials. Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM), showed the particle morphology and the core-shell structure respectively. (1)H-NMR and FT-IR showed the structure of core.