Polymerization of monomer 4-vinylpyridine (4VP) and N,N-dimethylacrylamide (DMAA) could be carried out using a system without organic initiator. It was found that metal catalyst (CuCl) and water played a vital role in this process through a series of control experiments. Polymers with high degrees of polymerization (Mp = 128739 for P4VP and Mp = 355122 for PDMAA) have been obtained by the addition of Au nanoparticles (AuNPs). Radical inhibitor and electron spin resonance (ESR) spin-trapping techniques have been used to analyze the polymerization process and identify the involvement of radicals in the reaction.