alpha-Ni(OH)(2) with hydrotalcite-like structure was prepared by precipitation of nickel acetate and sodium carbonate aqueous solution with the mediation of ethylene glycol at 393 K. Thermal calcination of this nickel hydroxide precursor at 573-1073 K resulted in the formation of fibrous nickel oxides with diameter of 4-8 nm and length of several hundreds of nanometers. Further reduction of these NiO samples with hydrogen at 773 K led to the formation of metallic Ni with fibrous-like morphology. Most promisingly, these novel nanostructured Ni materials showed much higher catalytic activities not only for the decomposition of methane to hydrogen and carbon nanofibers, but also for the hydrogenation reactions of unsaturated organic compounds.