Oxygen evolution reaction (OER) influences some important renewable energy technologies such as water splitting. Although many OER electrocatalysts have been studied to surmount this difficult problem, the development of a highly active, inexpensive and sustained OER electrocatalyst is still a great challenge. In this study, we report a novel, cost-effective cobalt selenide (coral-like CoSe) electrocatalyst with high current density (similar to 97.5 mA cm(-2) at 1.606 V vs. RHE) and strong durability in alkaline media. The chronoamperometric response of coral-like CoSe electrocatalyst can remain 98% of its initial current density after 10000 s at the overpotential of 350 mV in 1 M KOH. The prepared coral-like CoSe electrode exhibits a low overpotential of 295 mV at a current density of 10 mA cm(-2) and a small Tafel slope of 40 mV dec(-1), which exceeds previously reported state-of-art RuO2 electrocatalyst and is much better than CoSe nanoparticles (CoSe NPs) and precursor Co(OH)(2) electrocatalysts. This work affords us a 3D Co-based electrocatalyst with high performance and strong durability under alkaline conditions, which can be applied to energy conversion and storage processes. (C) 2016 Elsevier Ltd. All rights reserved.