To provide a vibration control material and an underground vibration control wall structure using this vibration control material, receiving little adverse influence of buoyancy by a rainfall, by providing a vibration control characteristic equal to or more than a conventional foaming body.

This vibration control material is used by being buried in the ground. The vibration control material is composed of a foaming body piece mold formed by joining a plurality of thermoplastic resin foaming body pieces. Porosity is set to 10 to 50%, and apparent density is set to 10 to 50 kg/m3.