Abstract: Based on ultraviolet (UV) accelerated aging tests, aging processes were tracked to study the effects of nano-TiO₂ antiaging agent on the surface aging behaviors and anti-aging ability of ethylene-propylene-diene monomer (EPDM). The anti-aging mechanism was also analyzed by Fourier transform infrared spectroscopy (FT-IR) and UV absorption spectroscopy. When the aging time prolongs, the surfaces of EPDM become rough, the chromatic aberration and the glossiness loss increase, the surface carbonyl index rises, while the rate of UV absorbance declines. FT-IR results demonstrate that with coating SiO₂, the photocatalytic degradation reaction of nano-TiO₂ is inhibited and the aging process of EPDM is postponed. After adding nano-TiO₂ anti-aging agent, the hole density decreases, the chromatic aberration and glossiness loss declines by 0.97 and 22.29%, respectively, the surface carbonyl index descends by 0.06, and the rate of UVabsorbance increases by 3.92%. The anti-aging ability of EPDM enhances.