OPG/RANK/RANKL system is an important signaling pathway in regulating bone metabolism, which plays key role in maintaining bone homeostasis. This paper focus on characteristic and regulation mechanism of OPG/RANK/RANKL system, and its current utility in the areas of bone metabolism diseases, pharmacodynamic and nutrient facts assessment. Furthermore, the prospect of OPG/RANK/RANK system in assessing nutrient requirement for bone development in laboratory animal was elaborated.