A new class alpha-MnO(2)nanofiber-based on assemblies of nanoparticles was synthesized to improve the availability of Mn atom for application in electrochemical storage. Furthermore, the effect of graphene quantum dots/polyaniline (GQD/PANI) on the structure and electrochemical performance of alpha-MnO(2)nanofiber was investigated. The MnO(2)nanofiber combined with GQD/PANI showed a larger specific capacitance of 1022.5 F g(-1)at 1.0 A g(-1)comparing to other MnO2-based electrode materials. The result was attributed to alpha-MnO(2)nanofiber with loosely assembled structure and GQD/PANI with good conductivity, providing more electrochemical active sites and reducing internal resistance. The working does not only report new MnO2-based electrode materials with high performance but also provides a facile method to synthesize alpha-MnO(2)nanofiber with a loosely assembled structure for various applications.