Surface modification of the silicon carbide nanoparticles (SiCP) by electroless nickel plating was performed. The XRD, TEM and XPS results showed that a nanoscale agglomerative nickel layer was coated on the SiCP, Dielectric permittivities of the original SiCP and nickel-coated SiCP were measured respectively in the GHz frequency range from 8 to 12 GHz. The real part and dielectric loss tangent of the nickel-coated SiCP were significantly enhanced. The origin of the enhancement was discussed in theory, and also explained by discussing practical influence factors. (c) 2006 Elsevier B.V. All rights reserved.