||Electrochemical supercapacitor has been considered as a promising energy storage device, due to high power density, fast charge/discharge time, and long cycle life. To attain high performance supercapacitor electrodes, we have fabricate polyimide-based carbon nanofibers via electrospinning and carbonization process, and have investigated their microstructures and electrochemical properties. For the purpose, poly(amic acid) (PAA), a precursor of aromatic polyimides, is synthesized from 3,3-dihydroxybenzidine and pyromellitic dianhydride in N,N-dimethylacetamide. PAA solution is electrospun into nanofibers, which are then imidized and carbonized to obtain final PI-derived carbon nanofibers (CNFs). The structures and morphology of PAA, PI, and CNFs are characterized by using NMR, FT-IR, Raman, and SEM. The electrochemical performance of the CNFs as electrodes of electrical double layer capacitors is evaluated by using cyclic voltammetry and galvanostatic charge/discharge test.