One-dimensional manganese oxide nanobelt bundles with layered structure have been synthesized by hydrothermally treating the precursor, K-type layered manganese oxide in a NaOH solution of 6.0 mol L-1 at 150 degrees C for 30 h. The obtained material is characterized by XRD, SEM, TEM and BET analysis. The manganese oxide nanobelt bundles are more than 50 mu m long and 20-50 nm wide, and the specific surface area is about 160 m(2) g(-1). The electrochemical property of the synthesized manganese oxide nanobelt bundles has been studied using cyclic voltammetry in a mild aqueous electrolyte. The manganese oxide nanobelt bundle exhibits good capacitive behavior and cycling stability in a neutral electrolyte system, and its initial capacitance value is 268 Fg(-1). (C) 2010 Elsevier B.V. All rights reserved.