The present invention provides a polymerizable composition that is suitable used as a temporary cement for implant use and a mobile tooth-fixing material. The present invention is a polymerizable composition that includes an acrylic block copolymer (a) having at least one polymer block A that mainly contains a (meth)acrylic acid ester unit and that functions as a hard segment and at least one polymer block B that mainly contains an acrylic acid ester unit and that functions as a soft segment, a polymerizable monomer (b), and a polymerization initiator (c).