The composite of hollow glass microspheres coated by SnO 2 nanoparticles has been successfully fabricated via sol-gel method. The phase structures, morphologies, particle size, shell thickness, chemical compositions of the composite have been characterized by XRD, FESEM, and EDX. The results show that SnO 2 coating on hollow glass microspheres can be achieved, and the coating layers are constituted by SnO 2 nanoparticles of mean size ca. 15 nm. The SnO 2 coating layers grow thicker with the increased concentration of SnCl 4 . The effects of parameters (reaction temperature, concentration of NaOH and SnCl 4 , and time) were investigated to yield SnO 2 coating on hollow glass microspheres, and the UV–vis absorption spectra of the composites were studied.