Objective:To investigate the protective effect of dimethylsulfoxide(DMSO) on axon degeneration.(Methods: Cultured) rat superior cervical ganglia were treated with DMSO(100%,10 ?l) per well to disconnect axons from the cell bodies.SCGs in DMSO control group were treated with a mixture of DMSO(10 ?l) and medium (2 ml) per well;in positive control group were transfected with herpes simplex virus over-expressing Wld~S protein and the cell body was eliminated;and in blank control group were treated with 10 ?l PBS.The separated axons were fixed with 4% poly formaldehyde at 0,4,8,12 and 24 h after treatment with DMSO for immunostaining with specific antibody to microtubulin.Thus,the changes of axonal structure were investigated.The axonal protein was collected and the degeneration of neurofilament was detected by Western Blotting.Results: In DMSO disconnected group,the axonal morphology and structure showed no obvious change at 12 h post disconnection,but slight degeneration was observed at 24 h post disconnection.The degradation of microtubulin was obviously slowed down and their axonal structures maintained intact 12 h later.The neurofilament could be detected 12 h after disconnection.The above changes in disconnected group were similar to those in positive control group.No obvious protective effects on axonal degeneration were observed in blank and DMSO control groups.Conclusion: Local high concentration of DMSO can delay axonal degeneration,which indicates that DMSO can be used for adjuvant treatment of neurodegenerative diseases.