Silver Poly (methyl methacrylate) PMMA nanocomposite thin films deposited on glass substrates by in-situ aerosol assisted plasma polymerization at atmospheric pressure and room temperature, from methyl methacrylate monomer in the presence of different concentrations of Ag nanoparticles (3%, 5%, 7%, and 9wt%). The average particles size for the silver nanoparticles was within 50nm. Metal polymer nanocomposite thin films were characterized by UV-VIS, XRD, and SEM the optical studies show that the energy band gap will be different according to the silver PMMA concentration. The XRD pattern indicates that the pure PMMA is amorphous where The XRD pattern of Ag nanoparticles in PMMA, all the refractions corresponded to the pure silver metal with cubic symmetry. SEM and the XRD reveal the presence of silver nanoparticle embedded into PMMA. It can be concluded that it can be prepared Ag PMMA nanocomposite thin films by aerosol assisted dielectric barrier discharge DBD plasma jet polymerization and control the optical energy band gap irregulars by controlling the experiment variables.