Nano-Mn3O4 +PbO2 composite electrode materials with different compositions are prepared by anodic composite electrodeposition in Pb2+ plating solution containing suspended nano-Mn3O4 particles (40–60nm). The particles are synthesized via one-step homogeneous precipitation at low temperature. The composite materials are characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM) analyses. The results indicate that the composite composed of γ-Mn3O4 and β-PbO2 is porous and quasi three-dimensional (3D), and its maximum electrochemically effective area ratio (R F) is 72. The capacitance performance of the composite is determined by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and charge–discharge test. The composite shows a high specific capacitance up to 338Fg−1.