Integrated and homogeneous nickel coating was achieved by electroless nickel-plating on pretreated PS microspheres. The resulting PS/Ni microspheres were characterized by SEM, EDS, XRD, and VSM. The hollow nickel microspheres were obtained by removing the PS core from the PS/Ni microspheres by a process of calcination. The thermogravimetric analysis was studied using a TGA system. The Ozawa and Coats-Redfern methods were exploited to calculate activation energy and determine thermal decomposition mechanism. The thermal decomposition mechanism of pure PS microspheres was also investigated to draw comparisons with the mechanism of PS/Ni microspheres. Although the essentials of thermal decomposition in both PS microspheres and PS/Ni microspheres is the decomposition of polystyrene, great differences in activation energies and mechanisms still exist. This may be attributed to the heat seclusion effect of nickel coating on the PS core. (C) 2008 Elsevier B.V. All rights reserved.