Pb3O4　could　react　with　organic　dyes　in　aqueous　solution　under　visible　light　irradiation,　in　which　Pb3O4　was　transformed　into　Pb-3(CO3)(2)(OH)(2)　along　with　oxidation　of　the　organic　dyes.　Cu2+　has　considerable　effect　on　the　reaction.　In　the　presence　of　Cu2+,　MO　(20　ppm)　and　RhB　(10(-5)　mol　L-1)　were　completely　degraded　under　visible　light　within　6　and　20　min,　respectively,　while　both　Pb3O4　and　Cu2+　keep　almost　stable　during　photodegradation.　The　mechanisms　of　the　reactions　with　and　without　Cu2+　ions　were　studied.　The　photochemical　system　of　Pb3O4　cooperating　with　Cu2+　ions　is　probably　used　for　the　treatment　of　organic　pollutants　in　water　under　visible　light.