An additive for rubber that enables a rubber composition to have excellent low heat generating property and processability, a rubber composition containing the additive for rubber, and a tire using the same are provided. A rubber composition comprises a hydrazone compound represented by the following Formula (I): where R1 and R2 each independently represent a hydrogen atom, an alkyl group with a carbon number of 1 to 16, or an alkenyl group with a carbon number of 2 to 6, and A represents a group represented by the following Formula (A-1) or Formula (A-2):