The design of efficient, cheap, and abundant oxygen evolution reaction (OER) catalysts is crucial to the development of sustainable energy sources for powering fuel cells. We describe here a novel Mn3O4/CoSe2 hybrid which could be a promising candidate for such electrocatalysts. Possibly due to the synergetic chemical coupling effects between Mn3O4 and CoSe2, the constructed hybrid displayed superior OER catalytic performance relative to its parent CoSe2/DETA nanobelts. Notably, such earth-abundant cobalt (Co)-based catalyst afforded a current density of 10 mA cm(-2) at a small overpotential of similar to 0.45 V and a small Tafel slope down to 49 mV/decade, comparable to the best performance of the well-investigated cobalt oxides. Moreover, this Mn3O4/CoSe2 hybrid shows good stability in 0.1 M KOH electrolyte, which is highly required to a promising OER electrocatalyst.