On　the　basis　of　the　determination　of　solubility　for　HgI2　in　KI　aqueous　solution　with　the　concentrations　of　0.25　mol/L,　0.50　mol/L,　0.75　mol/L　and　1.00　mol/L,　respectively,　the　solubility　curves　of　HgI2　was　drawn.　The　result　indicates　that　a　large　increase　in　solubility　of　HgI2　as　the　concentration　of　KI　aqueous　solution　increases　in　solution　which　shows　only　a　small　temperature　dependence.　As　the　concentration　of　KI　aqueous　solution　increasing,　the　temperature　dependence　for　solubility　of　HgI2　increases.　Based　on　the　obtained　relevant　information　for　properties　of　HgI2-KI-H2O　system,　the　KI　aqueous　solution　with　appropriate　concentration　of　1.00　mol/L　was　used　for　the　solvent　of　HgI2.　Top-seeded　solution　growth　was　applied　to　crystal　growth　of　HgI2　by　slowly　cooling　the　system,　and　the　bright　red,　transparent　HgI2　crystal　with　the　mass　of　17.4　g　was　obtained.　©,　2014,　Chinese　Ceramic　Society.　All　right　reserved.