A hydrogenated nitrile rubber composition, which comprises 100 parts by weight of hydrogenated nitrile rubber having a Mooney viscosity ML1+4 (100° C.) of 100 or less, an acrylonitrile content of 30-50%, and an iodine value of 28 or less, 60-250 parts by weight of carbon fibers, and 12-70 parts by weight of a polyfunctional group-based cocross-linking agent having a molecular weight of 150-500, and a viscosity (20° C.) of 3-120 mPa·s. The composition can further contain 30-150 parts by weight of carbon black and/or 60 parts by weight or less of graphite. The resulting hydrogenated nitrile rubber composition enables higher loadings of carbon fibers without lowering the kneadability and the molding processability, thereby improving the abrasion resistance of seal materials cross-linking molded from the composition.