Fibroblast growth factor 19 (FGF19) is one of the members of the fibroblast growth factor family, and has been shown to regulate the bile acid balance. Recent studies have revealed that FGF19 plays an important role in glucose, lipid and protein metabolism, which could induce glycogen and protein synthesis, suppress gluconeogenesis and triglyceride and cholesterol synthesis in liver. These new findings of FGF19 may pave a new way for the treatment of metabolic diseases such as diabetes mellitus.