We report a study on the growth process, induced by thermal treatments, of Au nanoparticles confined in a quasi-one dimensional geometry on SiO2 surface. Narrow stripes, 150 nm width, of Au nanoparticles on the SiO2 surface were generated by a combination of electron beam lithography and Au sputter-deposition. Then, annealing processes are performed to induce the growth of the nanoparticles. The mean size, spacing and surface density of the nanoparticles were quantified, as a function of the annealing temperature, by scanning electron microscopy analyses. The evolution of such parameters, as a function of the annealing temperature, allows us to infer information about the nanoparticles growth mechanism.