In　order　to　meet　the　demands　of　future　high-temperature　solar　thermal　power　generation,　37　kinds　of　mixed　carbonate　molten　salts　were　prepared　by　mixing　potassium　carbonate,　lithium　carbonate,　sodium　carbonate　in　accordance　with　different　proportions　in　this　paper.　Melting　point　of　molten　salt,　as　the　most　important　basic　character,　is　the　primary　parameter　to　select　molten　salt.　Melting　point　and　decomposition　temperature　are　measured　by　Simultaneous　Thermal　Analyzer.　The　results　show　that　melting　points　of　major　ternary　carbonates　are　close　at　around　400°C　and　decomposition　temperatures　of　most　ternary　carbonate　are　between　800　and　850°C.　In　accordance　with　energy　variation,　when　the　system　is　cooled　from　the　molten　state,　precipitates　of　crystalline　phases　is　orderly.　Crystallization　temperatures　of　some　samples　are　much　higher　than　their　melting　points.　Therefore,　through　comparative　experimental　study　of　heating　and　cooling,　10　kinds　of　mixed　carbonates　with　low　melting　point　and　crystallization　temperature　were　selected　primarily.　Then,　latent　heat,　density　and　thermal　stability　of　these　mixed　salts　were　studied.　Copyright　©　2012　by　ASME.