Mesoporous transition metal disulfide WS2 are facilely grown on the Ni foam substrate with 3D nanoflowers morphology and large surface area. The as-obtained WS2/Ni exhibit high performances for water oxidation in 1.0 M NaOH solution, which are much superior to those of the state-of-the-art RuO2/Ni and previously reported oxygen evolution catalysts. The WS2/Ni electrocatalyst manifests the high performance, displaying a very low overpotential of 0.335 V at 20.0 mA cm(-2) and much improved durability. The facile and controllable synthesis is promising for the rational design of electrocatalyst for the renewable energy conversion.