In this study, thermal-treatment-derived variations of the thermoelectric characteristics of ZnO nanofibers (NFs) are examined. NFs that were prepared by electrospinning were transformed into n-type ZnO NFs after they were exposed to thermal heating for 30 min at 550 degrees C. For the ZnO NFs, the Seebeck coefficient decreased from -132.1 mu V/K to -44.6 mu V/K over the heating-time range of 30 min to 120 min, while the electrical conductivity increased from 2.07 x 10(-3) S/m to 0.18 S/m.