Recently, there has been an immense interest in the fabrication of composite nanoparticles, such as core-shell structural materials [1-6]. These core-shell composite particles may show special properties different from those of the core or shell particles. Thus, Au or Ag nanoparticcles were coated by silica. The silica shell not only stabilizes the colloidal Au nanoparticles, but also influences their optical property [3,6]. Furthermore, Halas et al.  have demonstrated that by varying the ratio of gold-shell to silica-core, the plasmon optical resonance of the Au shell and silica core strongly shifts across the visible spectrum and into the infrared region. Core-shell particles can be used as building blocks for different devices including tunable Photonic-Band-Gap (PBG) structures. Herein, we report on the fabrication of such particles with emphasis on the preparation of the Au nano-shells coated polystyrene (PS) with a diameter of about 700 nm.