Enhancing　the　specific　heat　capacity　of　molten　salt　is　very　beneficial　to　reduce　the　cost　of　generation　electricity　of　solar　thermal　power.　In　the　present　work,　ternary　carbonates　nanofluids　of　K2CO3-Li2CO3-Na2CO3　(4:4:2,　mass　ratio)　with　SiO2　(5　nm,　10　nm,　15　nm,　20　nm,　30　nm,　60　nm)　nanoparticles　were　prepared　by　using　a　two　step　solution　method.　The　specific　heat　capacities　of　sample　are　measured,　and　the　mechanism　is　discussed.　The　results　indicates　that　the　specific　heat　capacities　of　ternary　carbonates　nanofluids　with　SiO2　(5　nm,　15　nm,　20　nm,　30　nm)　increases　at　around　the　same　level.　However,　the　enhancement　of　ternary　carbonates　nanofluids　with　SiO2　(60　nm)　significantly　decreases.　Moreover,　the　specific　heat　capacity　of　ternary　carbonates　nanofluids　remains　stable　during　thermal　cycling　in　thirty　times.　The　decomposition　temperature　of　ternary　carbonates　nanofluids　is　up　to　853.9.　The　nanostructures　formed　in　ternary　carbonates　nanofluids　may　be　the　main　mechanism　responsible　for　the　enhanced　specific　heat　capacity.　©　2017,　Science　Press.　All　right　reserved.