In the comparison of the solidi®cation characteristics of supercooling directional solidi®cation (SDS) with constrained directional solidi®cation (DS) and with the consideration of the inheritance of supercooled melt, the SDS technique established with the combination of melt supercooling and traditional DS was proposed. An exploring study on SDS techniques was also conducted using appropriate facilities, designed and manufactured by the authors' laboratory and the deep supercooling of Cu±5.0%Ni alloy, and its DSs were implemented. q