Nano-Au/silica composite has been synthesized by using nitrided mesoporous silica material as host. The nitridation treatment of mesoporous silica, i.e. SBA-15, with ammonia caused the generation of –NH x groups on its surface. After impregnation with aqueous solution of HAuCl 4 and following reduction, highly-dispersed gold nanoparticles with uniform sizes were formed in the channels of the nitrided host. The samples were characterized by FTIR, XRD and TEM techniques. The results showed that the nitridation treatment was an alternative and effective way to modify the surface properties of the silica host for immobilizing gold nanoparticles. It was supposed that the interaction between the surface –NH x groups and gold precursors was the key to immobilizing gold in the channels.