Supramolecular polymerization is influenced by many factors, especially the stiffness of the polymers, which is directly related to cyclization of the polymers. We have proposed a supramolecular "ring opening" polymerization system with DNA molecules to study the ring-chain equilibrium of supramolecular polymerization. The molecular weight of the supramolecular polymers was characterized by Asymmetric Flow Field Flow Fractionation, and the diffusion coefficient of the supramolecular polymers was characterized by Fluorescent Correlation Spectra. Tuning the ratio of the "ring opening" strand, the length of the DNA monomers and temperature could change the ring-chain equilibrium, thus influence the molecular weight and diffusion coefficient. This strategy has offered us a useful platform to dig into the kinetic mechanism of supramolecular polymerization.