Abstract: To prepare and characterize the hydroxyl-bridged dimeric platinum compound,a degradation product of cisplatin in aqueous solution.The compound was prepared via aquation of cisplatin,followed by irradiation at 313 nm.The chemical structures were characterized by elemental analysis,ESI-MS,1H NMR,along with X-ray crystal structure.The compound was determined to be a dimeric platinum(Ⅱ) complex with two hydroxyl groups as its bridged ligand.There are two expected Pt(Ⅱ) square planes.The angle formed between the planes is 2.7°,suggesting the two planes are actually in the same plane.The length of Pt-Pt is 3.095 and two nitrate ions lies outside the coordinated sphere.