Co 3 O 4 nanoarchitectures with controlled morphologies and Co 3 O 4 @MnO 2 core/shell arrays have been fabricated via a facile hydrothermal method. Co 3 O 4 nanowires and nanosheets have been obtained by the thermal annealing Co(OH) 2 precursors. Furthermore, the Co 3 O 4 nanowires are used as the scaffold to deposit MnO 2 nanosheets to form Co 3 O 4 @MnO 2 core/shell arrays. MnO 2 shells coated on the surface of Co 3 O 4 nanowires show a porous-rich structure, which promotes the electrochemical performance of the electrochemical capacitor. The Co 3 O 4 @MnO 2 core/shell arrays exhibit high specific capacitance of 1280 F/g, good rate performance, and excellent cycling stability. The growth roadmap in this work is a facile strategy to design and synthesize transition metal oxides and hydroxide hierarchical hetero-structures for the next generation electrochemical energy storage, catalysis, and gas sensing applications.