Objective：To investigate the effect of fasting plasma glucose（FPG） on the severity of cerebrovascular stenosis in patients with ischemic stroke. Methods：Three hundred and seven patients with ischemic stroke were divided into three groups according to the level of FPG. The clinical features and imaging data of patients were analyzed. Results：With the increase of FPG，the number of diseased vessel，the severity of cerebrovascular stenosis were increased. In patients with age< 60 years，the cerebrovascular stenosis in FPG 5.6-7.0 mmol/L group and FPG > 7.0 mmol/L group was severe than that in FPG < 5.6 mmol/L group. And in patierts with age≥60 years the stenosis in FPG > 7.0 mmol/L group were more serious than that in FPG < 5.6 mmol/L group. Conclusion：Stenosis of cerebrovascular in ischemic stroke increased along with the increase of FPG. The vascular stenosis in patients less than 60 years old with FPG > 5.6 mmol/L or over 60 years old with FPG > 7.0 mmol/L is more serious than that in patients with FPG < 5.6 mmol/L.