The physical properties of aged NEPE-5 under 65 ℃ were measured by using the dynamic mechanical analysis and the change of dynamic properties were analyzed. The data varied regularly with the increase of aging time when the temperature ranged from -20 ℃ to 40 ℃. The specific heat around vitrification and viscoelastic coefficient and all decreased with the increase of aging time. At high temperature section (0~40 ℃)，the storage modulus and the loss modulus changed little when the samples were aged for less than 60 days, whereas increased greatly with the increase of aging time after aged for 60 days.