Polymerizable composition and norbornene resin

A polymerizable composition comprising a norbornene-based monomer, a metathesis polymerization catalyst, and a coordinating compound containing a phosphorus atom,

• wherein the metathesis polymerization catalyst is a ruthenium-carbene complex represented by General Formula (1) or (2) below, and
• the coordinating compound containing a phosphorus atom is contained in an amount such that 170 to 2000 mol of phosphorus atoms are contained relative to 1 mol of ruthenium atoms in the metathesis polymerization catalyst:
• where in General Formulae (1) and (2) above, R1 and R2 each independently represent a hydrogen atom;
• a halogen atom;
• or a C1 to C20 organic group which may contain a halogen atom, an oxygen atom, a nitrogen atom, a sulfur atom, a phosphorus atom, or a silicon atom;
• and these groups may be substituted, or may be bonded to each other to form a ring;
• X1 and X2 each independently represent any anionic ligand;
• L1 and L2 each represent a heteroatom-containing carbene compound or phosphines;
• and at least one of L1 and L2 is phosphines.