A new technique has been developed to obtain large supercooling for Fe-C alloys. A mother alloy was prepared by the addition of rare earth metal (REM) of 0.75mass% to molten Fe-C alloy of 2kg. A specimen weighing 0.08kg was taken out o f the mother alloy and charged into an alumina crucible. The procedure of melting and freezing of the specimen was repeated in a Tammann furnace. The surface layer of the solidified ingot was removed after being repeated the procedure of melting and freezing for several times, and then the procedure was further repeated. By this procedure the supercooling of 100K was obtained. Furthermore the non-dendritic structure and uniform concentration of carbon were obtained by supercooling.