The following thermo-physical properties are determined for Al-34%Mg-6%Zn（in wt.%） and Al-28%Mg-14%Zn alloys used for thermal energy storage applications

such as the specific heat capacity including solid and liquid state;the mass density in the temperature range 30～500℃;the melting temperature and the latent heat of fusion.The properties are measured by differential scanning calorimetry（DSC） and H-90 type dilatometer.The test results show that the melting temperature and latent heat of fusion for the two alloys are 454℃

447℃ and 314.4kJ/kg

303.2kJ/kg

respectively.Their density heated from room temperature to melting temperature are decreased by（1.05%）

（1.09%）

respectively.Their specific heat capacity are growing with the temperature increasing before the beginning of phase change

and are 1368.5 J·kg-1·K-1

1203.6 J·kg-1·K-1 at 445℃

respectively.The change of specific heat capacity are great due to the existing of latent heat of fusion during the phase transformation process.The measured results mentioned above are credible from the points of view of comparing with the value of theory calculation and error analysis of data.The mechanism that the effect of alloy compositions and phases on these properties is discussed in this paper.