Abstract: Objective　To compare the effects of tocilizumab and azathioprine on the visual function after optic neuritis (ON) in patients with neuromyelitis optica spectrum disorder (NMOSD). Methods　Data of 67 NMOSD patients treated in Tianjin Medical University General Hospital were retrospectively analyzed. There were 33 patients (42 eyes) received treatment of tocilizumab and 34 patients (44 eyes) received treatment of azathioprine. The visual acuity chart, optical coherence tomography and visual evoked potential (VEP) were used to detect changes of visual acuity, macular optic ganglion cell complex (GCC) thickness, peripapillary retinal nerve fiber layer (pRNFL) thickness and VEP P100 amplitude and latency from baseline in the two groups. Results　There were no significant differences in the Logarithm of the minimum angle of resolution (LogMAR) visual acuity and low-contrast visual acuity between baseline and after treatment with tozumab and azathioprine, while the thickness of macular GCC and peripapillary pRNFL were thinner, and VEP P100 amplitude reduced in the both groups (P＜0.05). The latency of VEP P100 was prolonged in azathioprine group (P＜0.01). Compared with the tozumab group, the amplitude of VEP P100 was significantly lower in the azathioprine group (P＜0.05). Conclusion　Neither tocilizumab nor azathioprine can reverse the process of optic nerve degeneration and atrophy after optic neuritis in NMOSD patients. However, compared with azathioprine, tocilizumab may help delay optic axonal degeneration.