Fretting is a low-amplitude reciprocating movement which may lead to seal failure, it is important to explore the fretting characteristic of a rubber seal in hydrogen atmosphere. In this work, a numerical model considering the effect of hydrogen swelling was presented to study the fretting behavior of a rubber seal. The fretting running condition was analyzed. Results showed that, the amplitude of reciprocating motion made a great effect on the fretting state of rubber seals, the O-ring seal in high-pressure hydrogen atmosphere exhibits a higher propensity to run in the sticking regime because of swelling effect. The fluctuation range of the peak Mises stress in hydrogen was much larger than that in air, leading to aggravating the fatigue failure of the rubber seal. It was more difficult to produce relative slip in hydrogen compared with in air, resulting in exacerbating the fretting wear of rubber seals. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.