Yellow CdS/wax nanocomposite spheres were fabricated in an aqueous solution by an emulsion method, in which the US nanoparticles were adsorbed on the surface of a wax core with positive charge by electrostatic self-assembly. A thin shell of SiO2 was then coated to the yellow CdS/wax spheres by the hydrolysis of Na2SiO3 in the same aqueous solution to enhance the optical and mechanical properties and the charge load of the composite spheres. The product was characterized by transmission electron microscopy, scanning electron microscope, atomic force microscopy, thermogravimetric analysis, and X-ray powder diffraction, which showed that the SiO2 walls of spheres were compact and part of US crystals dispersed inside, the density of composite spheres being about 1.3 g/cm(3), which match most of the suspensions. Fourier transform infrared spectroscopy, and energy dispersive X-ray spectrometry showed the component of composite spheres. Dynamic light scattering showed the diameter distribution of composite spheres was between 100 similar to 400 nm. Zeta-potential measurement proved that the SiO2/CdS/wax spheres had a higher charge load, and Ultraviolet-visible spectra showed that the SiO2/CdS/wax spheres had a better optical property. Therefore, this type of composite spheres had the merits of low density and strong durability in environments. The response behavior of the microencapsulated electronic ink of the composite spheres has been measured. This novel method is expected to produce various inorganic/organic nanocomposite spheres with potential application in the fields of electronic paper and other material science.