The specific conductivity of the pure binary NaCI-AICI, molten salt system was measured In the temperature range 175-400 °C and with the mole fraction of AICI" *mci,> ranging from 0.497 to 0.000. Sulfur, aluminum metal, and sodium chloride were dissolved In the NaCI-AICI, solvente at ea. 250 °C, forming polymeric NaAISCI,. The specific conductivity of these melt• was measured In the range 0 < * * < 0.08. All conductivity data are given as a polynomial function of temperature and composition.