Abstract: The thermal stability of Al-34%Mg-6%Zn alloy with trace amount of beryllium as thermal energy storage materials under the conditions of a large number of melting / solidification thermal cycles and the corrosion of the alloy with respect to stainless steel (SS304L) and carbon steel (steel C20) during thermal cycle process were studied.The investigated alloy as latent heat storage materials had good thermal stability since the melting temperature and the latent heat of fusion were decreased by 3.06 ℃ and 1.95% for the alloy after 1 000 cycles,respectively.The results of corrosion test showed that SS304L (corrosion rate 0.10 mm/a) might be considered to be more suitable than C20 (corrosion rate 0.18 mm/a) in long-term thermal storage applications.