Hydrogen energy utilization from water splitting relies on the successful development of earth-abundant, efficient, and stable electrocatalysts for oxygen evolution reaction (OER). Herein, aligned Ni-Co hydroxide nanoplate arrays are formed on Ni foam substrate via hydrothermal process. These hydroxide nanoarrays are grown according to a pattern-growth mode, and all nanoplates align themselves in the same direction to construct a domain coinciding the Ni domains. Due to the large electrochemically reactive surface and the strong coupling interaction between nanoplates and Ni substrate, the nanoarrays electrode exhibits low overpotentials (270 mV at 10 mA cm(-2)), small Tafel slopes (59 mV.dec(-1)), and strong stability.