Abstract: The influences of hot-pressing temperature and volume percent of the second-phase particles A1N on the dielectric properties of SiO₂-A1N composite materials were investigated. It could be found that with increasing the hot-pressing temperature, the dielectric constant of SiO₂-A1N composites increased and loss tangent decreased; while for the same hot-pressing temperature the dielectric constant and loss tangent of the composites increased with increasing the contents of the second-phase particles A1N. The dielectric constant and loss tangent of 10vo1.%A1N-SiO₂ composites (1MHz) were 4.1 and 9.0 × 10^-4 respectively, indicating that SiO₂-A1N composites had excellent dielectric properties. The obtained results were discussed from the viewpoint of phase composition and microstructure of SiO₂-A1N composites.