This work was undertaken to study deep underccoling of Al65Cu20Fe15 alloy melt in Al- Cu - Fe system by cyclic superheating and cooling method. By means of the denucleating technique, Al65Cu20Fe15 alloy melt has been undercooled to 98 K under its melting point, and Al - Cu - Fe icosahedral quasicrystalline ball of 6 mm in diameter was produced. Moreover,the first phase to nucleate will change with the degree of underccoling in alloy melt. It was confirmed that quasicrystal forming ability can be enhanced by increasing the level of denu-cleating in Al65Cu20Fe15 alloy.