The Ir@Pt core-shell spherical nanoparticles with Pt deposited on Ir cores were synthesized for the first time using successive reduction method based on epitaxial growth. The Ir@Pt/SiO2 core-shell structure catalysts were used in the three-way catalysts of controlling automobile exhaust emission, which exhibited high catalytic activity of NO reduction in three-way catalytic reaction. [GRAPHICS] .