Polyvinyl alcohol (PVA)/Ag nanocomposite films are successfully prepared. Silver nanoparticles are generated directly in PVA matrix by reduction of metallic precursor silver nitrate (AgNO3) with UV-irradiation. UV-visible spectra of the films show effects of silver ion concentration, irradiation power and irradiation time on preparation of silver nanoparticles. Size and space distribution density of the Ag nanoparticles can be controlled by varing irradiation condition combined with adjusting concentration of Ag+ ion. So the surface plasmon resonance peak of the film can be shifted to 406 nm, matching very well with laser wavelength of 405 nm in optical recording system. Scanning electron microscope (SEM) images show narrow size distribution and uniform, intensive, and relatively independent dispersion of the obtained nanoparticles which is pure silver confirmed by X-ray photoelectron spectroscopy (XPS) analysis. Atomic force microscope (AFM) scans reveal that laser direct write carries out successfully on the films.