A heat-insulating composition, a method of preparing the same, and a heat-insulating element using the same are provided. The heat-insulating composition includes water, a super absorbent polymer (SAP), a hydrophobic powder, and a silicon binder. The method of preparing a heat-insulating composition includes producing a gelatinous aqueous solution by mixing water and a super absorbent polymer (SAP) with each other, obtaining a waterborne mixture by adding a hydrophobic powder to the gelatinous aqueous solution to be accompanied with stirring, and adding a silicon binder to the waterborne mixture. The heat-insulating element includes a heat-insulating substrate, and a heat insulation composition layer formed on the heat-insulating substrate.