A supermolecular compound, {8-hydroxyquinolineH44+·SiW12O404-·2H2O} was synthesized by hydrothermal reaction with silico-tungstic acid and 8-hydroxyquinoline. The crystal of the compound belongs to monoclinic system, space group P21/n, with a=1.282 6(6) nm, b=2.292 7(4) nm, c=2.092 0(6) nm, β=95.495(2)°, Z=4, V=6.124 1(7) nm3, Dc=3.791 g·cm-3, μ=22.568 mm-1, F(000)=6 200, R1=0.029 3, wR2=0.069 3, GOF=1.079. Su-permolecular compound is composed of one SiW12O404- with Keggin structure, four protonated cations of 8-hydroxyquinoline, two hydrones. Thermal analysis results showed that the anionic skeleton construction of heteropoly acid in compound decomposed approximately at 349.0 ℃. CCDC: 622142.