The eutectic and liquidus temperatures of water-potassium chloride and water-magnesium chloride systems were measured using DSC in this study. The plots of liquidus temperatures as a function of composition show good agreement with partially available literature data. The measured eutectic temperatures of water-potassium chloride and water-magnesium chloride mixtures are -11.1degreesC and -33.2degreesC, respectively. The heating curve of the eutectic mixture of water-potassium chloride was also used to confirm the eutectic temperature. The eutectic compositions of water-potassium chloride and water-magnesium chloride systems are 19.5 NW1o KCl and 21.6 wt% MgCl2, respectively. The eutectic composition of water-potassium chloride was also estimated from the eutectic fraction data. In comparison with the available literature data, the DSC measurement and the eutectic fractional transformation methods provide consistent and accurate results. The solid state heat capacity data of the nearly eutectic binary mixtures were also evaluated from the measured DSC data.