Aim To validate the efficacy of different doses of atorvastatin for patients with symptomatic intracranial atherosclerotic stenosis （sICAS）. Methods 120 patients with sICAS were enrolled and randomly divided into three groups. Patients in the three groups were given 10 mg/d, 20 mg/d, and 40 mg/d of atorvastatin respectively, for one year. All patients were also given other aggressive medical therapy. Evaluation variables,including changes in degree of stenosis, and perfusion-related parameters derived from computed tomography perfusion （CTP） imaging from baseline to one year during the study period, were used to compare the benefits of these three statin therapies. Results After one year of atorvastatin therapy, patients in the three groups had an obvious improvement of degree of stenosis, improvement of degree of stenosis was significantly better in the 40 mg/day group. Patients in the three groups had an obvious increase in relative cerebral blood flow （rCBF） and relative cerebral blood volume （rCBV） levels at the end of one year. However, patients in the 40 mg/day group experienced a reduction in relative time to bolus peak （rTTP） at the end of one year while those in the other two groups showed an increase in rTTP. Conclusions Improvement of degree of stenosis, and perfusion-related parameters were all significantly better by long-term use of atorvastatin.