A new supramolecular compound, {[Cd（L）2]2[PMo12O40NO3]·CH3CN·2H2O}n 1 （L is 1,4-bis（4-imidazolyl）-2,3-diaza-1,3-butadiene）, based on Cd（II）-Schiff-base and Keggin- type [PMo12O40]3- was synthesized via self-assembly and structurally characterized by elemental analysis, infrared spectroscopy, and single-crystal X-ray diffraction analysis. The crystal is of triclinic, space group P1 with a = 12.0128（11）, b = 13.6196（13）, c = 13.9995（13） , α = 103.868（2）, β = 95.225（2）, γ = 101.024（2）°, V = 2160.0（3） 3, Z = 1, C34H39N26O45Cd2Mo12P, Mr = 2938.96, Dc = 2.259 g/cm3, μ = 2.276 mm-1, F（000） = 1400, the final R = 0.0565 and wR = 0.1613 for 4973 observed reflections with I 〉 2σ（I）. The crystal structure can be described by the packing of Keggin anionic and Metal-Schiff-base cationic layers.
