Rubber reinforcing cord and fiber reinforced material

A rubber reinforcing cord, suitably used as a reinforcing material of rubber materials such as tires, belts and hoses and excellent in fatigue resistance, comprises a carbon fiber bundle having an elongation at break of 1.7% or more impregnated with a resin composition containing a rubber latex. The cord has an initial gradient (dM/dy) at y = 0 of the bending load M - deflection y curve of the cord of 1000 N/m or less. A substantially twist-less rubber reinforcing cord comprises a carbon fiber bundle having an elongation at break of 1.7% or more and impregnated with a resin composition containing a rubber latex. The number of twist of the cord is 10 per meter or less.