Objective: To evaluate the changes of peripapillary and macular retinal vasculature parameter in nonarteritic anterior ischemic optic neuropathy (NAION) patients. Methods: In this case-control study,eighteen consecutive patients (18 eyes) who were clinically diagnosed with atrophic NAION (at least 3 months after onset of symptoms) between October 2017 and June 2018 were included. Twenty healthy outpatient patients (20 eyes) with normal eye examination were selected as the control group. The optic nerve head and macular was scanned by optic coherence tomography angiography (OCTA) for all subjects.The following parameters, including peripapillary retinal nerve fibre layer (pRNFL), macular ganglion cell complex (GCC), whole en face image vessel density (wiVD) of the radial peripapillary capillaries (RPC), peripapillary RPC vessel density (ppVD), superficial capillary plexus (SCP), deep capillary plexus (DCP), and parafoveal vessel density (pfVD) were measured. Multi-factor regression analyses were used to analyze the effects of blood flow parameters on the incidence of NAION, LogMAR BCVA, pRNFL and GCC. Pearson correlation between ppVD and pRNFL was analyzed. Results: Compared with the control group, pRNFL thickness, RPC wiVD and ppVD of the NAION group were significantly reduced (t=-6.567,-6.958, -6.668, P<0.001) and the SCP wiVD, DCP wiVD and GCC thickness were significantly reduced (t=-6.226, -2.760, -6.340, P<0.001). NAION development was related to ppVD (b=0.502, OR=1.653,P=0.045). The LogMAR BCVA of the NAION group was related to SCP wiVD (b=-0.726, P=0.003), the pRNFL thickness was related to ppVD (b=0.883, P=0.001), and significant correlations were also found between ppVD and pRNFL thickness in the superior and inferior sectors (r=0.946, P<0.001; r=0.680,P=0.031). Conclusions: OCTA provided detailed visualization of the peripapillary and macular retinal capillary rarefaction predominating near larger vessels, correlated with visual acuity loss and pRNFL thickness thin in affected eyes of NAION whose disease course was more than 3 months. The sparser the ppVD of the affected eye is, the more likely NAION is to develop, and the poorer visual acuity is correlated with thinner pRNFL and sparser of SCP wiVD.