This paper presented the changes of surface properties of high-temperature-vulcanized (HTV) silicone rubber used for outdoor insulators due to corona discharge. It is found that the intact angle and surface resistivity of HTV silicone dramatically decreased due to corona discharge, but completely recovered in a very short duration of recovery. With measuring the surface voltage after corona charging, it was confirmed that the surface porper쇼 became activated states due to the generation of excited radicals and reactive groups. The results of the chemical analysis showed that C-H bonds and Si-$CH_3$bonds were broken due to corona discharge and silica-like bonds (SiOx, x=3~4) increased. It is thought that the above changes lead to the loss of surface hydrophobicity of HTV silicone rubber. However, co개na discharge induced the increase of diffusible low molecular weight(LMW) chains, which could lead to recover the surface hydrophobicity. The aging and the recovery mechanism due to corona discharge based on our results were discussed