Based on Mie scattering theory,we design three kinds of nanostructures (Au,Au-dielectric,dielectric-Au)and study the effects of the structure parameters and the background refractive indexes on optical scattering properties of nanostructures.It is demonstrated that by increasing the outer radius of the nanoparticle,the resonance position will show a redshift and the linewidth increases.In addition,the dipole approximation is no longer valid.Experimentally discovered that comparing with the results of the Au spherical nanoparticle,the scattering peak enhances and the linewidth becomes narrower as the increase of the core radius in Au-dielectric core-shell nanostructures under the dipole approximation.For the dielectric-Au core-shell nanostructure,it is found that when the thickness of Au layer decreases,the strong coupling between the spherical mode and the cavity mode makes the resonance peak position redshift and the scattering peak increase significantly.With the increase of the refractive index of the dielectric core or shell,the mode will be further red shifted for Au-dielectric or dielectric-Au core-shell nanoparticles.Finally,by introducing gains into the dielectric layers of the Au-dielectric core-shell nanoparticles or reducing the dielectric-Au core-shell nanoparticles in silica environment considering the practical application,the narrow-band and strong scattering in the visible range can be realized.These results will provide important theoretical basis for the fabrication of the high performance transparent display screens.