Four bioactive peroxovanadium (pV) complexes-bpV(ox), bpV(bipy), bpV(phen). and bpV(pic), ([VO(O-2)(2)L](n-), where ligand L = oxalic acid dianion (ox), bipyridine(bipy), 1,10-phenanthroline(phen), and pyridine-2-carboxylic acid (pic), were synthesized,and characterized by V-51 NMR, H-1 NMR, C-13 NMR, ESI-MS, IR and elemental analysis. All H-1 and C-13 peaks were,assigned by 2D H-1-H-1 peaks were assigned by 2D H-1-H-1 COSY, HMQC and HMBC. Their stereochemical structures in solution were discussed according to the NMR signals of organic ligands. The descending stability order of complexes in aqueous solution determined by V-51 NMR is bpV(phen), bpV(bipy) bpV (pic) and pV(ox). The predominant decomposition patterns of these complexes were proposed on the basis of electrospray ionization MS (ESI-MS) and V-51 NMR. This work will facilitate the studies of interactions between pV complexes and target biomolecules in solution so as:to clarify structure-function relationship of these:bioactive complexes.