Reaction of CuCl2 center dot 2H(2)O and trivacant Keggin polyoxoanion Na-9[A-alpha-PW9O34]center dot 7H(2)O in the presence of ethylenediamine/1,2-diaminopropane (en/enMe) under hydrothermal conditions led to five novel inorganic-organic hybrid polyoxotungstates (POTs):[Cu(en)(2)](2)[Cu(en)(2)(H2O)](2)[Cu(H2O)(2)][Cu-4(H2O)(2)(B-alph a-PW9O34)(2)]center dot 2H(2)O(1), [Cu-6(mu(3)-OH)(3)(en)(3)(H2O)(5)(B-alpha-PW9O34)]center dot 6H(2)O (2), Na-6{[Cu-6(mu(3)-OH)(3)(en)(3)(H2O)(2)(B-alpha-PW9O34)](2)[Cu-4(H2O)(2)( B-alpha-PW9O34)(2)]}center dot 2 H(2)en center dot 8H(2)O (3), [Cu-6(mu(3)-OH)(3)(en)(3)(H2O)(3)(B-alpha-PW9O34)]center dot 4H(2)O (4), [(Cu6Cu4I)-Cu-II(mu(6)-O)(OH)(18)][Cu-6(mu(3)-OH)(3)(enMe)(3)(H2O)(3)(B-alpha-PW9O34)](4)center dot 4H(3)O center dot 2H(2)O (5). 1 is a new 1D chain constructed from alternate tetra-Cu-II sandwiched units [Cu-4(II)(H2O)(2)(B-alpha-PW9O34)(2)](10-) and dinuclear [Cu-2(II)(H2O)(6)](4+) units. 2-5 are a series of novel transition-metal substituted polyoxometalates (TMSPs) comprising hexa-Cu-II substituted {Cu6PW9} units (Cu-6=Cu-6(mu(3)-OH)(3), PW9=B-alpha-PW9O34, Scheme 1). 2 is an unusual monomer. 3 is an unprecedented tetramer built by two types of TMSP units, [Cu6PW9(en)(3)(H2O)(2)] and [Cu-4(II)(H2O)(2)(PW9)(2)](10-). 4 is a novel chain assembled from [Cu6PW9(en)(3)(H2O)(3)] units by double-bridging mode. Most interestingly, 5 is a open framework made by [Cu6PW9(enMe)(3)(H2O)(3)] units, in which the novel decacopper oxygen clusters, [(Cu4Cu6II)-Cu-I(mu(6)-O)(OH)(18)](4-) formed in situ, are encapsulated into the channels, and 5 represents the first decametallic-cluster-containing open framework built by TMSP units. 2-5 all contain the hexa-Cu-II substituted POT unit {Cu6PW9L3(H2O)(n)} (L = en/enMe, n < 6) made by {Cu6L3(H2O)(n)} core and trivacant Keggin PW9 fragments. Moreover, 3-5 can be viewed as combining derivatives of 2 through substituting water ligands on hexa-Cu-II {Cu6L3(H2O)(n)} units by terminal oxygen atoms of PW9 units. Importantly, the Cu-II-polyhedra Jahn-Tell/pseudo-Jahn-Teller distortion plays a crucial role in the formation of 1-5. The magnetic behaviors of 2-5 show antiferromagnetic interations between the Cu-II ions in the hexa-Cu-II cluster.