The title compound, {(H3O)4(NH4)4[Mo8O28]?2H2O}n 1, has been synthesized from the reaction of Zn(OAc)2 and (NH4)6Mo7O24?4H2O in aqueous solution at ambient tempe- rature, and its crystal structure was determined by X-ray single-crystal analysis with the following crystallographic data: monoclinic system, space group P21/n, a = 9.5234(6), b = 11.3235(8), c = 14.8812(10) ?, β = 107.467(2)o, V = 1530.77(18) ?3, Z = 4, F(000) = 1336, μ = 3.293 mm-1 and Dc = 3.037 g/cm3. The final R = 0.0619 for 2691 observed reflections (I > 2σ(I)). X-ray crys- tal structure analysis showed that the novel one-dimensional chain compound is built up by basic {Mo8O28} units via single μ2-O, and such chains are further linked into a three-dimensional net- work by hydrogen bonds. The title compound, {(H3O) 4 (NH4) 4 [Mo8O28] • 2H2O} n1, has been synthesized from the reaction of Zn (OAc) 2 and (NH4) 6Mo7O24 • 4H2O in aqueous solution at ambient temperature, and its crystal structure was determined by X-ray single-crystal analysis with the following crystallographic data: monoclinic system, space group P21 / n, a = 9.5234 (6), b = 11.3235 (8), c = 14.8812 , β = 107.467 (2) o, V = 1530.77 (18)? 3, Z = 4, F (000) = 1336, μ = 3.293 mm-1 and Dc = 3.037 g / cm3. The final R = 0.0619 for 2691 observed reflections (I> 2σ (I)). X-ray crys- tal structure analysis showed that the novel one-dimensional chain compound is built up by basic {Mo8O28} units via single μ2-O, and such chains are further linked into a three-dimensional net-work by hydrogen bonds.