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Nickel nanowire arrays with preferential growth of (111), (200) and (220) lattice planes were prepared via a modified templateassisted electrodeposition method respectively. As a HER electrocatalyst, (220) preferred orientation nickel nanowire arrays exhibited higher catalytic activity and stability in alkaline solution, and the hydrogen evolution overpotential was as low as 128 mV at the current density of 10 mA · cm-2. The performance is attributed to the higher surface energy of the (220) lattice plane of nickel nanowire arrays as the exposed surface and more active sites participate in HER process, which is beneficial to charge transfer and decrease of activation energy of reactions. Simultaneously, the activation energy of exposed surface evaluated directly by calculating with First-principles correspond to the trend of the experimental results, catalytic activity (220) > (200)> (111) lattice plane in the hydrogen evolution process. The strategy of using crystal anisotropy to improve catalytic performance can be extended to the synthesis of other nanocrystals with higher activity and high-energy surface catalysts. [ABSTRACT FROM AUTHOR]