Metallic nickel particles have been selectively synthesized via chemical reduction using a static magnetic field. Our results demonstrated that both reduction temperature and magnetic-field strength were the crucial factors in determining the final particle shapes. Upon subjecting a 0.02 T magnetic field, the particles change from sea urchin-like, through spherical, to one-dimensional (1D) in shape with decreasing the reduction temperature. In the synthesis of 1D structure, sphere-chains with fluctuant diameter are assembled under weaker magnetic field while relatively smooth nanowires are formed under stronger one. Thermal analysis of the particles was also investigated. (C) 2009 Published by Elsevier B. V.