Abstract: An object of the present invention is to provide a modeling composition, which sets at room temperature by just the addition of a prescribed amount of water, is excellent in elasticity, has a high gel strength, is excellent in terms of safety, and with which a modeling material can be molded readily at low cost. The modeling composition of the present invention contains 100 weight parts of glucomannan, 1 to 100 weight parts or more preferably 2 to 75 weight parts of a basic curing agent, 9 to 500 weight parts or more preferably 50 to 250 weight parts of a neutral solute, 0 to 30 weight parts or more preferably 1 to 20 weight parts of a tempering agent, and 0 to 300 weight parts or more preferably 1 to 150 weight parts of a modifier.