Although　molten　salts　have　been　used　in　large　scale　in　the　experimental　or　commercial　solar　thermal　power　plants,　systematic　studies　on　thermal　performence　of　mixed-salts　are　lacking.　Four　eutectic　nitrate　salts　with　low　melting　point　were　choosed　by　the　analysis　of　the　TG　curve　and　DSC　curves　with　nine　binary　mixtures　of　salts　with　different　mass　ratio,　the　specific　heat-temperature　curve　were　obtained　after　further　analysis　of　the　DSC　curve　and　experimental　correlations　were　fitted.　Potassium　carbonate,　lithium　carbonate,　sodium　carbonate　are　mixed　in　accordance　with　the　different　proportions,　36　kinds　of　mixed　molten　salt　are　obtained.　The　data　of　melting　point,　decomposition　temperature,　specific　heat,　latent　heat　and　use　temperature　range　were　obtained　by　the　analysis　of　the　TGA　and　DSC　curves　of　36　salts.