Glassy carbon nanofibers (g-CNFs) with diameter of ca. 45 nm were prepared from electrospun cellulose nanofibers (CelluNFs) by two sequential steps: stabilization and carbonization. The CelluNFs were stabilized at 400 degrees C and carbonized at 850 and 1400 degrees C to produce g-CNFs. The morphology and crystallographic structure of the precursor, stabilized and carbonized nanofibers were characterized by field emission scanning electron microscopy, transmission electron microscopy (TEM), selected-area electron diffraction, and Raman spectroscopy. It was found that the stabilization treatment was very effective in maintaining the nanofiber morphology of the final product g-CNFs. TEM images revealed that the g-CNFs carbonized at 1400 degrees C showed ribbon-like curved single carbon layer networks throughout the sample. These layers were randomly stacked without any particular sequence, and were looped. Raman spectra confirmed that the g-CNFs contained low content of graphitic crystallites. The I-D/I-G values indicated that most carbons of g-CNFs are in the amorphous state. The electrical conductivity was dependent on the graphitic microstructure in the g-CNF. It reached to 93.5 S/cm for the g-CNF carbonized at 1400 degrees C. The g-CNF with good conductivity may find applications in the carbon-based nanodevices.