Pancreatic β-cell dysfunction is a central component of the pathogenesis of pediatric diabetes. MicroRNA (miRNA) have become one of the most encouraging and fruitful fields in biological research, and have been implicated as new players in the pathogenesis of diabetes and diabetes-associated complications. The role of miRNA in diabetes begins with the development of pancreatic islets. Fibroblast growth factor (FGF)-21 enhances glucose uptake in adipocytes, protecting transgenic animals from diet-induced obesity when overexpressed, and lowers blood glucose and triglyceride levels in diabetic animals (when administered); therefore, it is a good way to treat diabetes. However, the mechanism of miRNA in regulation of FGF21 is not known. In this study, FGF-21 was predicted to be the target of miR-577. Therefore, we investigated the effects of miR-577 on β-cell function and survival by targeting FGF-21. We demonstrated that, although FGF-21 does not acutely stimulate insulin secretion in isolated islets from normal rats, it increases insulin secretion and insulin content in diabetic islets and protects β-cells from apoptosis via the activation of extracellular signal-regulated kinase 1/2 and Akt signaling pathways.