Co3O4 grown on nickel foam and carbon fiber substrate with different morphologies were synthesized by hydrothermal synthesis method using different filling volume. The structure and morphology of the products were characterized by X-ray diffraction (XRD),Fourier Transform Infrared Spectroscopy (FTIR)and scanning electron microscopy(SEM). The results showed that by changing the filling volume can prepared the cobalt oxide products with thesame phase and different morphologies in the hydrothermal reaction system.Electrochemical properties of Co3O4grown on nickel foam electrode were characterized by cyclic voltammetry (CV), chronopotentiometry, and electrochemical impedance measurements method.The results indicated that the70%filling volumereaction system prepared uniform Co3O4nanocluster arrays,which exhibited noticeable pseudocapacitive performance with a high capacitance of 961F?g-1 at 1A?g-1in 2mol ? L-1KOH electrolyte, and 76% was maintained when the current density increased to 20A?g-1.