Abstract: In this research aged natural rubber(NR) blocks were sliced and tested.The aging characteristics inside NR isolation bearings were revealed.Furthermore,a finite element model of NR isolation bearing was built and the suitable constitutive law for NR was discussed,then the performances of aged NR bearings were predicted through finite element analysis.The proposed prediction method of aged NR isolation bearings' performances was validated through comparing the simulation results with the test results of a 38-year old Pelham bridge NR bearing.