Abstract: Subarachnoid hemorrhage (SAH) is commonly seen in neurosurgical emergency with high mortality, high morbidity, high medical expense and poor prognosis, and frequently accompanied with stress hyperglycemia after the aneurysm rupture and its hemorrhage. Lots of researchers focus on the relationship between hyperglycemia and delayed cerebral ischemia with poor prognosis. In this paper, we aim to review the mechanism under stress hyperglycemia after aneurysmal subarachnoid hemorrhage and its relationship with the prognosis of SAH.