The polymerization of norbornadiene (NBD) initiated by a novel ruthenium (Ru)(II) complex (3) containing 1,1'-pyridine-2,6-diylbis[3-(dimethylamino)prop-2-en-1-one] (1) as ligand has been investigated. Ru complexes exhibit more catalytic activity in the ring-opening metathesis polymerization (ROMP) of NBD when activated with trimethylsilyldiazomethane (TMSD). The influence of the various experimental parameters such as reaction time and temperature, nature of the solvent and catalyst, ratio of the NBD/Ru, and TMSD addition has been investigated. The polymers have been obtained in high yields with a relatively low polydispersity index for ROMP and a high (M) over bar (n) and (M) over bar (w) values in a monomodal distribution. Their structures have been determined by means of FTIR and H-1-NMR spectroscopy. Thermal properties have been determined via thermogravimetric analysis and DTG methods. The NBD polymerization results that initiated by Ru-based catalyst coordinated to amine ligand have been compared to initiated by [RuCl2(p-cymene)](2). (C) 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 127: 1691-1696, 2013