ELASTOMER REINFORCEMENT CORD

Provided is an elastomer reinforcement cord with improved rust resistance. An elastomer reinforcement cord includes metal filaments and a polymer material. The elastomer reinforcement cord has a multi-strand structure which includes: at least one core strand formed by twisting plural metal filaments and together; and two or more sheath strands each formed by twisting plural metal filaments and together, the sheath strands being twisted together around the core strand. An intra-sheath-strand filling rate a, which is a ratio of the area of the polymer material with respect to an intra-sheath-strand gap region A, is 52% or higher, and an inter-strand filling rate b, which is a ratio of the area of the polymer material with respect to an inter-strand gap region B, is 75% or higher.