A norbornene monomer bearing cyclic dithiocarbonate moiety (NB-DTC) was successfully synthesized from the corresponding precursor having epoxy moiety by its reaction with carbon disulfide. NB-DTC underwent the ring-opening metathesis polymerization (ROMP) catalyzed by a ruthenium carbene complex to give the corresponding poly(norbornene). The dithiocarbonate moiety incorporated into the side chain of the obtained poly(norbornene) reacted with amine to afford the corresponding thiourethane moiety with thiol group, which underwent oxidative S-S coupling and/or addition reaction to the C-C double bond in the main chain, leading to formation of a cross-linked polymer. (C) 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 49: 1097-1103, 2011