Objection To investigate axonal regeneration of retinal ganglion cells of Nogo-A/B/C knockout mice after optic nerve crush in vivo and in vitro.Methods The left eye of every mice was crushed by optic nerve forcep and right of every mice as normal control.The left eye of C57BL/6 mice was used as experimental control.Nogo-A/B/C mRNA was investigated in optic nerve of Nogo-A/B/C knockout mice and C57BL/6 mice with in situ hybridization.Partial optic nerve injury model was induced in the left eyes by a special designed optic nerve clip with 40 gram power for 9 seconds at optic nerve 1mm behind the eyeball.Frozen section were immunostained to investigate GAP-43 by Immunofluoroscence.