Surface modification of beta-FeSi2 by ZnO is verified to be an effective way to prevent oxidation and enhance thermoelectric (TE) properties of beta-FeSi2. A simple approach is developed to fabricate well-covered, high-density and stable ZnO nanoparticles-coated beta-FeSi2 (ZnO@beta-FeSi2). First, beta-FeSi2 (n-type Fe0.98Co0.02Si2) particles were prepared by mechanical alloying (MA) and pre-treated in sodium oleate solution to increase the polarity of the surface. Then, the pre-treated beta-FeSi2 particles were successfully coated by ZnO nanoparticles during sol-gel process. Compared with that of uncoated beta-FeSi2, antioxidation and thermoelectric performance of ZnO@beta-FeSi2 materials is improved distinctly. (C) 2011 Elsevier B.V. All rights reserved.