We report here a simple,mild,and environmental friendly approach to synthesize Au-SiO2 composite nanospheres,which present a route to decorate preformed amine functionalized SiO2 nanospheres by in situ formation of Au nanoparticles at three different concentrations of Au precursor(HAuCl4).Herein,silane coupling agent(KH-550)is acted as an intermediary to connect Au nanoparticles to the surfaces of SiO2 nanospheres,which is also helpful for avoiding the aggregation of Au nanoparticles.The crystal structure,chemical elements,morphology and photocatalytic property of Au-SiO2 composite nanospheres were analyzed with transmission electron microscopy(TEM),X-Ray powder diffraction(XRD),UV-vis-spectrophotometer(UV-vis),and X-ray photoelectron spectroscopy(XPS).Analytical results demonstrate that Au nanoparticles(4-9 nm)are homogeneously distributed on the surface of SiO2 nanospheres,which have good FCC crystal structure.Moreover,these Au-SiO2 composite nanospheres exhibit good catalytic properties for the reduction of organic dyes,which may have promising applications in photocatalysts and wastewater treatment.