A polymerizable composition comprised of a mixture of a norbornene-based monomer and a metathesis polymerization catalyst which is solidified by cooling is provided. Preferably, the norbornene-based monomer has a freezing point of 20° C. or more, more preferably the metathesis polymerization catalyst is a ruthenium-carbene complex. According to the present invention, it is possible to provide a polymerizable composition which is excellent in storage stability and which enables industrial production of small resin shaped articles which are excellent in stability of quality.