Abstract: Objectives To evaluate the risk factors of nonarteritic anterior ischemic optic neuropathy(NAION)in a population of China and to provide theory basis for clinical decision. MethodsDemographic features and clinical data of NAION were recorded.Cerebral infarction(CI)patients were also collected as control group.Systemic evaluations including whole blood chemical test,brain MRI,carotid artery ultrasound and fundus photography were performed in NAION and CI patients.The fundus photography and cup/disk ratio were also acquired in a healthy eontrol group with matched age and gender.Statistical analysis was done by SPSS11.5 software. Results Thirty-eight NAION patients and 40 CI patients with intact data were included.Fundus photography and cup/disk ratio were acquired in 41healthy individuals.No statistically significant difference regard to incidences of diabetes,male gender and lipid metabolic abnormalities was found between NAION and CI patients(P>0.05).Hypertension,clinicaI and sub-clinical cerebral vascular disease and carotid artery stenosis were statistically more common in CI patients than in NAION patients(P<0.01,O.05).Cup/disk ratio was statistically significant smaller in NAION than in CI patients while no statistical difference(P>0.05)was found between the CI group and healthy individuals. Conclusions NAION shared similar risk factors with cerebral infarction,but exposure of these risk factors was different between NAION and cerebral infarction.Hypertension,cerebral vascular disease and carotid artery stenosis were more common in cerebral infarction while diabetes.male gender and lipid metabolic abnormalities were similar.Small cup/disk ratio was an independent and the most important risk factor for NAION.