Silicon oxide nanowires (SiO(X)NWs) was decorated with 3- to 6-nm-sized Au nanoparticles by direct deposition of Au on the nanowire surface without any surface pretreatment. The nanowire surface was uniformly coated with Au nanoparticles with a density of 2x10(12) particles cm(-2). It was found that the Au nanoparticles grown on the SiO(X)NWs was much finer in size compared to the Au nanoparticles deposited on a flat SiO(2) substrate because of the high curvature of the nanowires and abundant surface defects resulting from the oxygen non-stoichiometry. Moreover, the particle size as well as the particle density can be tuned at will by simply altering the growth condition of the SiO(X)NWs. The tuning of the Au particle provides an opportunity to tailor the Au nanoparticles for desired applications.