In　the　present　work,　the　new　eutectic　composition　of　KNO2-KNO3-K2CO3　ternary　salt　for　sCO2　solar　thermal　power　generation　is　predicted　by　thermodynamic　calculation,　then　the　thermophysical　properties　of　the　eutectic　salt　are　investigated　by　experiments　combined　with　theoretical　calculation,　further　studies　are　focused　on　its　corrosivity.　The　results　show　that　the　predicted　ternary　molten　salt　is　confirmed　as　0.259KNO2–0.687KNO3–0.054K2CO3.　Due　to　mixing　a　small　amount　of　K2CO3,　the　upper　limit　of　the　operating　temperature　of　the　eutectic　salt　can　reach　750.1　°C,　and　the　melting　point　and　the　freezing　point　have　a　good　thermal　stability　in　the　heating-cooling　cycles.　The　calculated　specific　heat　is　lower　than　the　measured　one　which　can　maintain　at　1.407　J/(g·K)　in　the　range　of　400–450　°C.　With　the　increase　of　temperature,　the　density　decreases　linearly　and　the　thermal　diffusivity　tends　to　increase,　thus　there　is　a　slight　growing　in　thermal　conductivity　with　an　average　value　of　0.3　W/(m·K).　The　novel　eutectic　salt　has　an　energy　storage　density　of　865　MJ/m3.　Although　containing　a　low　concentration　of　K2CO3,　the　eutectic　salt　shows　low　corrosion　to　310S　stainless　steel.　After　the　corrosion　test　of　240　h　at　600　°C,　the　mass　loss　of　stainless　steel　maintains　a　constant　at　0.067　mg/cm2.　The　above　results　indicate　that　0.259KNO2–0.687KNO3–0.054K2CO3　eutectic　salt　is　a　promising　high-temperature　thermal　storage　material　for　solar　thermal　power　generation.　©　2023