We found out the factors: age ≥ 60, syncope at onset, Glasgow Coma Scale ≤ 9 points, hemiplegia, World Federation of Neurosurgical Societies scale ≥ 3, Acute Physiology and Chronic Health Evaluation II scale > 9, intraventricular haemorrhage and the diameter of the aneurysm ≥5 mm appeared more in delayed cerebral ischemia group than non delayed cerebral ischemia.