Root caries was the major dental problem in old age patient. It causes tooth fracture. The diagnosis, treatment and preventive of root caries were reviewed in this article. Etiology of root caries was root exposure oral environment, than poor oral hygiene and xerostomia causes dental plaque accumulation. Treatment was filling the cavity with filling material but glassionomer cement for xerostomia patient was first choice. Preventive of root caries may be remove dental plaque first, than use fluoride contain oral rinse, and chlorohexidine rise for preventive initial root caries occurred is the best.