Objiective To observe the changes of angioarchitecture of the optic disc in cats eyes after radial optic neurotomy (RON). Methods Ten healthy adult cats underwent unilateral RON randomly in 10 eyes as an operative group in this trial, and the fellow eyes (10 eyes) were as the control group. The colophony samples of vascular angioarchitecture of 20 eyes were made 90 days after RON and scanning electron microscope was used for the observation. Results In the control group, the blood supply of optic disc mainly came from the short posterior ciliary artery, pial artery, and retinal ciliary artery; the choroidal capillary vessels around the optic disc didnprime;t take part in the blood supply in the anterior area; retinal central vascular system and complete arterial circle around the optic nerves were not seen. In the operative group, a V-shaped defect of the optic disc, retinal blood vessels and choroidal capillary vessels was found at the surgical incision; no injury of retinal blood vessels and choroidal large vascular layer was seen, and neovascularization at the incision were not found. Conclusions RON may cause the vascular defect of the optic disc and the peripheral local tissues. The depth of the incision doesnprime;t reach the Zinn-Hallers circle. (Chin J Ocul Fundus Dis, 2007, 23: 170-172)