Abstract: A hydrogenated nitrile-butadiene rubber(HNBR)/hindered phenol composite was successfully prepared by adding 3, 9-bis 1, 1-dimethyl-2［β-(3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy］-ethyl-2, 4, 8, 10-tetraoxaspiro［5,5］-undecane (AO-80) into HNBR. The microstructure of the HNBR/AO-80 composite was characterized by DSC, XRD, DMA and SEM. The results show that with the increasing of AO-80 amount, the loss tangent of composite gradually increases and the corresponding peak temperature shifts to higher temperature. In the HNBR matrix, AO-80 exists in the forms of vitrified microballoon particles and vitrified aggregates, both of which are capable of improving damping properties of HNBR by interaction of hydrogen bonds.