A low-molecular-weight water-soluble elastin having a molecular weight of about 10,000 to 30,000 and a high-molecular-weight water-soluble elastin having a molecular weight of about 30,000 to 300,000 are provided, 79% to 84% of the constituent amino acids of the elastin comprising proline, glycine, alanine, and valine, 2% to 3% comprising aspartic acid and glutamic acid, 0.7% to 1.3% comprising lysine, histidine, and arginine, and 0.2% to 0.4% comprising desmosine and isodesmosine. The low-molecular-weight water-soluble elastin that is obtained may be used in a functional food or a medicine. Such a high-purity water-soluble elastin may be produced by obtaining pure insoluble elastin by subjecting animal body tissue to a collagen removal treatment and then fragmenting the insoluble elastin by means of a solubilizing liquid. It may be produced simply, merely by adjusting the concentration of an alkaline solution and the reaction time without recovering insoluble elastin from the animal body tissue.