Abstract: The high-temperature accelerated aging tests in hydraulic oil with temperatures of 110 ℃, 130 ℃ and 150 ℃ were carried out on a nitrile-butadiene rubber. Then the effects of aging time on the tensile property and hardness of the rubber were studied and the aging behavior was analyzed. The service life of the rubber was also predicted by using Arrhenius equation. The results show that during the aging process, under the combined effects of oil swelling, crosslinking and chain broking, the tensile strength of the nitrile-butadiene rubber first kept unchanged then decreased, the hardness first decreased then increased and the maximum percentage elongation decreased exponentially. According to the maximum percentage elongation data, the service life predicted by Arrhenius equation of the nitrile-butadiene rubber in 25 ℃ hydraulic oil was 2 836 d, which was equivalent to the real life. The prediction result was relatively accurate.