A difunctional methacrylate monomer, 2,6-dicarbomethoxy-1,6-heptadiene (DCHD), was cyclopolymerized by group-transfer polymerization (GTP). The polymerization could be initiated by silyl enol ether in the presence of bifluoride or bibenzoate salt as a catalyst. "Living" cyclopolymerization was achieved to give a linear polymer of a cyclohexane repeat unit without any network structure. The polydispersity of poly(DCHD) was in the range of 1.23-1.28. The structure of the resulting polymer was characterized by C-13 NMR, H-1 NMR, and IR spectroscopy. Block copolymers with controlled sequence lengths were prepared from methyl methacrylate and n-butyl methacrylate.