The Co3O4 nanosheets electrode have been fabricated on Ni foam by a facile synthesis process including the electrodeposition of Co(OH)2 precursor followed by subsequent thermal transformation of precursor to Co3O4. The resulting Co3O4 nanosheets electrode exhibits an ultrahigh specific capacitance of 6469Fg−1 at a current density of 5mAcm−2, exceeding their theoretical value. Moreover, at density of 15mAcm−2, the specific capacitance maintains 4127Fg−1, with 81.6% retention after 2000 charge-discharge cycles. The work confirms the promising application of Co3O4 nanosheets as an efficient electrode for supercapacitors, and also offers a facile strategy to design and synthesis Co3O4 electrode with enhanced specific capacitance.