Aneurysmal subarachnoid hemorrhage (SAH) is a frequent worldwide cause for stroke with a mortality of around 30%. Worldwide, almost 500 000 patients have aneurysmal SAH annually.An incidence of 2-16 cases of spontaneous SAH per 100 000 person-years was reported in a recent meta-analysis . Surgical treatment of aneurysms is essential in the acute phase of aSAH patients, either by surgical clipping or by endovascular embolization. Although there are many factors that influence the prognosis of patients with aSAH, cerebral vasospasm (CVS) and delayed cerebral ischemia (DCI) are the main factors contributing to the high mortality rate (30-40% within 30 days) and poor long-term functional prognosis of patients after aSAH. Cerebral vasospasm (CVS) is defined as focal or diffuse temporary narrowing of vessel diameter due to contraction of smooth muscle in the arterial wall, which can be detected by digital subtraction angiography (DSA), transcranial ultrasound Doppler (TCD), magnetic resonance (MR), and CT angiography (CTA) or visualised during intraoperative.The prevalence of CVS after aSAH is 67% , with symptomatic patients (symptomatic vasospasm) in 30-40% of them and leading to ischaemic events in 10-45% of patients. It usually begins 3-4 days after bleeding, peaks at 7-10 days and finally resolves at around 14-21 days. There is no effective treatment to prevent cerebral vasospasm events.Shuxuening Injection is a sterilized aqueous solution made by extraction of Ginkgo biloba. The study aims to clarify the clinical study of the efficacy and safety of Shuxuening Injection (10ml/branch) for the prophylactic of cerebral vasospasm (CVS) after aneurysmal subarachnoid hemorrhage.