To provide a cord for reinforcing rubber, having good adhesiveness to the rubber, and exhibiting excellent fatigue resistance to stress deformation such as flexural deformation; and to provide a fiber-reinforced rubber material.

The cord for reinforcing the rubber is obtained by attaching 5-20 pts.wt. of a random copolymer of ethylene oxide (EO) and propylene oxide (PO) to 100 pts.wt. of a carbon fiber bundle. The fiber-reinforced rubber material is obtained by reinforcing the rubber with the cord for reinforcing the rubber.