A method for fixing patterned nanoparticles onto a substrate was developed by combining photopolymerization with a laser manipulation technique. Nanoparticles were dispersed in ethylene glycol containing monomer, crosslinker, and photoinitiator, and gathered at the focal point of a trapping laser beam (1064 nm) just on a glass substrate. Local photopolymerization within and around the nanoparticles assembly was induced by additional irradiation of a pulsed-laser beam (355 nm), resulting in generation of polyacrylamide containing nanoparticles. The polymerized assembly was evaluated by atomic force microscope observation. By scanning both trapping and excitation laser beams, patterned nanoparticles could also be fixed on a glass substrate.