Polymerization of multifunctional monomers could produce polymers with different functionalities and novel macromolecular architectures. However, the ability to control the homopolymerization of multivinyl monomers (MVMs) has always been a challenge. Here we demonstrate that the homopolymerization of acrylate based MVMs can be kinetically controlled via Cu-0-mediated controlled/living radical polymerization in the presence of additional Cu-II, which enables the efficient promotion of intrarnolecular cydization and suppression of intermolecular cross-linking. The gelation is effectively delayed over ca. 40% monomer conversion in the concentrated polymerization system ([M] = 40.9 wt %), which is far higher than the Flory-Stockmayer theory predicts. Moreover, closer inspection of the synthesized polymers reveals that single-chain cyclized/knotted polymeric nanoparticles (SCKNPs) are formed due to the nature of one-pot in situ intramolecular reaction and self-cyclization of the propagating polymer chains. This facile, method opens a new avenue to the design and synthesis of a broad range of novel single-chain cyclized/knotted polymeric materials.