The low-melting CaCl2-NaCl-Al2O3 materials were used as the electrolyte of the low temperature aluminium electrolysis. The electrical conductivity and density of the materials were measured by the Continuously Varying Cell Constant Technique, ac-techniques, and Archimedes method. The materials were composed of 71wt.%~87wt.%CaCl2 (corresponding NaCl), NaCl and Al2O3(without and saturated). The measurement temperature ranges were 550°C~800°C. The results showed that Additive Al2O3 decreased the electrical conductivity of the materials, and resulted in the increase of the activation energy of conductance. The function relationship between the electrical conductivity and temperature was linear, and conformed to the Arrhenius equation. Increasing the CaCl2 content decreased the electrical conductivity of the materials, but the density was increased. With the increase of the CaCl2, the decrease scope of the electrical conductivity was small and the increase trend of the density was slow down. The decisive factor of the electrical conductivity of the materials was temperature.