The dynamic mechanical properties denoted by storage modulus (E') and loss factor (tan delta) of binary and ternary systems consisting of carboxylated nitrile rubber (XNBR) filled with organic hindered phenol compound 2,2'-methylenebis(6-tert-butyl-4-methylphenol) (AO-2246) or/and short carbon fiber (SCF) were investigated. DMA results of binary XNBR/AO-2246 system showed that by addition of AO-2246, the tan peak maximum of XNBR was remarkably increased up to 3.5, and its peak position was also significantly shifted to room temperature, demonstrating that XNBR/AO-2246 composite is a promising damping material. Nevertheless, application Of Such XNBR/AO-2246 composite is limited due to its relatively low E' value above glass transition temperature. Therefore, to develop a high-performance damping material with high tan delta peak and high modulus as well as controllable tan delta peak position, the combination of organic hybridization and fiber reinforcement were adopted. DMA analysis of various ternary XNBR/AO-2246/SCF systems revealed that by introduction of SCF, the E' value of XNBR/AO-2246 was increased remarkably while the tan delta peak maximum was still higher than 2.5. Thus, a new type of XNBR-based high-performance damping material was developed. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 114: 2655-2661, 2009