Two sandwich-type complexes Na-gn(Cu(im)(4)(H2O)(2))(1.51)(Cu(im)(4)(H2O))(n) [{Cu(im)(4)}{Na(H2O)(2)}(3)(Cu-3(im)(2)(H2O)}(XW9O33)(2)](2n)center dot(xH(2)O)(n) (im = imidazole, X = Bi (1), Sb (2), x = 42.5 (1), 40 (2)) have been synthesized and structurally characterized. Basic frameworks of 1 and 2 are built from sandwich-type [{Na(H2O)(2)}(3{)Cu-3(im)(2)(H2O)}(XW9O33)2](9-) (X = Bi or Sb) anions and [Cu(im)(4)](2+) cations. The Cu2+ and Na+ ions in the central belt are coordinated by alpha-[XW9O33](9-) units, im, and water molecules to form {CuO4(im)}, {CuO4(H2O)}, and {NaO4(H2O)2} groups in which Cu2+ ions are partially modified With im ligands. These groups connect alternately forming a six-membered ring including six alpha-[XW9O33](9-) units. Neighboring anions are further linked by [Cu(im)(4)](2+) cations to display an unprecedented anionic chain, which is first observed in sandwich-type tungsto-bismuthate (-antimonite) system. Two kinds of isolated copper complexes and sodium ions are located as counterions, which cause three-dimensional packings of 1 and 2 to present interesting cage structures. The magnetic properties for 1 and 2 both indicate dominant antiferromagnetic interactions among trinuclear Cu(II) clusters.