Abstract: Disclosed is a preparation method of manufacturing a thermoelectric nanowire having a core/shell structure. The preparation method of thermoelectric nanowire includes preparing a substrate provided with an oxide layer formed thereon, and forming a Bi thin film on the oxide layer, heat treating a structure produced during forming the Bi thin film to induce compressive stress due to differences in coefficients of thermal expansion between the substrate, the oxide layer and the Bi thin film, to grow a Bi single crystal nanowire on the Bi thin film, and cooling the substrate of a structure on which the nanowire is grown to a low temperature, and sputtering a thermoelectric material on the Bi single crystal nanowire in a cooled state to manufacture a thermoelectric nanowire having a core/shell structure of Bi/thermoelectric material.