An unprecedented asymmetrically modified bivanadium-capped Keggin polyoxometalate (POM), {AsMo12O40(VO)- [VO(H2O)]}center dot[Cu(4,4'-bipy)](5)center dot H2O (1) (bipy = bipyridine), has been hydrothermally synthesized and structurally characterized by a routine technique. Single-crystal X-ray diffraction analysis reveals that compound 1 exhibits a unique (3,4,6)-connected 3D framework with a (6(2).8(1))(2)(8(3))(2)(6(4).8(2))(2)(6(1).8(14)) topology, constructed from {AsMo12O40(VO)[VO(H2O)]}(5-) polyoxoanions modified by six {Cu(bipy)}(n) coordination polymeric chains. The asymmetrical polar coordination mode has never been found in the POM chemistry hitherto. It is also the first example of the bivanadium-capped POM as an anionic template to construct a 3D framework with the highest connection number of bicapped POW Additionally, by just changing the length of the organic ligand, a new compound {[AsMo12O40(VO)(2)][Cu(bpe)](2)}center dot[Cu(bpe)]center dot[H(2)bpe]center dot H2O (2) (bpe = bis(4-pyridyl)ethylene), has been obtained, in which the {AsMo12O40(VO)(2)} sections are modified by double monotrack {Cu(bpe)}(n) coordination polymeric chains to form a "rail-like" 1D structure.