Longgu is the fossil of ancient mammals which was used as a common kind of mineral medicine. Longgu is always used to treat neurological diseases. Currently, the quality standard of Longgu is incomplete. Moreover, because of the non-renewable nature of the resource and the increase of national protection of fossils, the clinical application of Longgu is facing a series of problems. As the discovery of the ingredient and the development of forging technology researchers launched to search the substitutes of Longgu. The article summarizes the usage and the study of Longgu, in order that we can discuss the modern usage and substitutability of Longgu.