We　report　a　new　Ag　nanoparticle-dispersed　polymer　nanocomposite　for　volume　holographic　recording　through　acrylic　photopolymerization.　The　initial　grating　buildup　dynamics　at　the　inhibition　stage　are　measured　at　various　Ag　nanoparticle　concentrations.　The　refractive　index　modulation　amplitude　as　large　as　0.0069　at　633　nm　is　seen　at　the　optimum　Ag　nanoparticle　concentration　of　1　wt.%　with　respect　to　the　monomer.　Electron　paramagnetic　resonance　measurements　show　that　Ag　nanoparticles　influence　both　the　generation　of　alkyl　radicals　and　the　scavenging　of　oxygen　in　free　radical　photopolymerization.　This　mechanism　intrinsically　determines　the　molecular　weight　of　polymer　being　formed　and,　thereby,　affects　the　refractive　index　modulation　amplitude　of　the　formed　grating　as　a　function　of　Ag　nanoparticle　concentrations.　Moreover,　we　confirm　that　two-beam　holographic　exposure　leads　to　a　periodic　assembly　of　dispersed　Ag　nanoparticles　using　a　dark-field　microscopy.　Our　results　suggest　a　simple　way　to　control　the　photopolymerization　and,　therefore,　to　tailor　polymers　for　practical　uses.