Railpad prevents damage of the tie and ballast by reducing the impact and high frequency vibration, which occurs when a vehicle load transfers to a tie. But elasticity of the railpad can decrease under vehicle load and over usable period. If that happens, railpad will become stiffer. Increase in stiffness of the railpad also translates into a rise in track maintenance cost because it accelerates the damage of the track. In this study, accelerated heat ageing test was performed to predict an expectable lifetime of the railpad. As a result, it was predicted to be about sixteen years at $25^{circ}C$ that life time of railpad using NR rubber from Arrhenius relationship. Also, it was predicted to be about thirty-two days at $100^{circ}C$. At this time, a standard rate of thickness change is approximately within 12%.