Abstract: Various environmental factors affect rubber and make it hard and brittle.Consequently,the rubber isolation bearing cannot fulfill deformation and energy absorption,and will eventually damage the safety of isolated structures.Aged rubber will prevent oxidation from progressing into the interior.Therefore the aging inside rubber isolation bearing is not uniform.Accelerated exposure tests are performed at different temperatures on some natural rubber (NR) blocks.The aged rubber blocks are sliced and the development of deterioration inside rubber blocks is quantitatively studied.Results show that NR at the block surface deteriorates fast,whereas the interior beyond a certain depth does not deteriorate.Based on the aging characteristics inside a NR block,an aging model is proposed to predict the aging inside rubber isolation bearings.