We have calculated the effects of short wavelengths on the effective permittivity and refractive index of configuration of dielectric and conducting nano-spheres. We simulate a type of refractive index material composed of metal and insulating dielectric nano-spheres, which are able to sustain the propagation of infrared or visible frequency electromagnetic waves known as surface plasmon polaritons. calculations for aluminum and four samples of insulator have been done. The results for these nanoparticles is good agreement with experimental results.