The dependence of power durability on temperature and input power has been studied in detail by using SAW filter with AlMgCu/Ti/AlMgCu/Ti 4-layered electrodes. In case of SAW filters, acceleration factors of degradation are temperature and input power. These 2 factors are not independent in actual SAW filters, but it is necessary to control the condition to keep the independency of these 2 factors in accelerated deterioration test. As the results of power durability estimation of 4-layered electrodes which had done in consideration of the point above, the activation energy of diffusion showed value of bulk diffusion level in the test using 800MHz band filters, and the dependence of input power was increase in proportion to the frequency of input power. Additionally, we successfully improved power durability of 4-layered electrodes by modifying the layered structure and increasing Mg content in AlMgCu alloy layers. In the former case, the dependency of input power didn't change but the absolute level against input power was improved. On the other hand, the dependency of input power and the absolute level against input power didn't change but the dependence of temperature is increase in the latter case.