Background　Cerebral vasospasm（CVS） is a common and serious complication of aneurysmal subarachnoid hemorrhage. Secondary brain ischemia and damage following CVS are the main factors for patient bad outcome or high mortality.　Objective　The aim is to clarify the effect of prevention and treatment in the perioperative fluid therapy and circulating blood volume management for CVS and patient better outcome following aneurysmal subarachnoid hemorrhage.　Content　We′ll review the etiology and pathophysiology of CVS following aneurysmal subarachnoid hemorrhage and how to prevent CVS by fluid therapy and triple-H therapy.　Trend　It might be helpful to make further researches in pathogenesis of CVS and how to prevent CVS by fluid therapy and circulating blood volume management.