Developing cheap composite nanoparticle systems that combines a high dielectric constant with good conductivity is important for the future of the electronic industry. In this study, two different sizes, 7.3 +/-2.2 and 5.6 +/- 1.9 nm, of HfO2@Au core-shell nanoparticles are prepared by using a high-temperature reduction method. The core shell nanoparticles are characterized by powder X-ray diffraction, high-resolution transmission electron microscopy (HRTEM), energy dispersive X-ray analysis (EDX), and UV-visible absorption spectroscopy. Hfo(2) exhibits no absorption in the visible region, but the HfO2@Au core-shell nanoparticles show a plasmon absorption band at 555 nm that is 25 nm red-shifted as compared to pure gold nanoparticles. According to transmission electron microscopy and energy dispersive X-ray analysis, the Hfo(2) particles are coated with approximately three atomic layers of gold.