The injury and dysfunction of the femoral head microvascular endothelial cells are associated with the pathogenesis of glucocorticoid-induced osteonecrosis of the femoral head (ONFH). Reports indicate that icariin (ICA) can enhance vascular roles and also inhibit endothelial cell dysfunction. However, it still remains unclear whether ICA can promote angiogenesis in glucocorticoid-induced ONFH. In this study, we investigate this hypothesis through in vitro and in vivo experiments. Results showed that 0.1 mg/mL hydrocortisone significantly suppressed bone microvascular endothelial cells (BMECs) proliferation while ICA at 10(-5) mol/L reversed this inhibition. ICA significantly promoted BMECs migration, tube formation, the angiogenesis-related cytokines expression and the activation of Akt. Furthermore, ICA enhanced Bcl-2 expression but diminished Bax expression. According to in vivo results, rats with ICA treatment exhibited a lower ratio of empty lacunae, higher volume of blood vessels and more CD31-positive cells. This study revealed that ICA promotes angiogenesis of BMECs in vitro and improves femoral head blood vessel volume of rats treated with glucocorticoid, suggesting the efficacy of ICA in the prevention of glucocorticoid-induced ONFH.