Heterogeneous Co(OH)2 nanoplate/Co3O4 nanocube hybrids with rich oxygen vacancies have been constructed through a controllable approach. The high surface areas of such unique nanohybrids together with abundant oxygen vacancies provide more surface active sites, which can facilitate the charge transfer and boost the exchange of intermediates. Specifically, the resultant Co(OH)2 nanoplate/Co3O4 nanocube hybrids display outstanding oxygen evolution reaction (OER) performances with a low overpotential of 281 mV at 10 mA cm-2 and excellent durability after continuous CV of 3000 cycles, shedding light for large-scale applications in practical water splitting.