Nickel nanochains assembled with submicrometer-sized flowers were synthesized through a mild hydrothermal method without any template and surfactant. Subsequently, nickel-gold metal composition nanostructures were also prepared by reduction reaction taking advantage of reducing property of nickel metal. The resulting chain superstructures were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy and the thermogravimetric analysis (TGA) measurement. This synthesis of such hierarchical structures implies a simple and inexpensive way to prepare bimetallic composite superstructures in a large-scale. Furthermore, these bimetallic composites could improve their antioxygenation properties. Published by Elsevier B.V.