A　ZnGe　oxynitride　semiconductor　was　prepared　by　a　solid-state　reaction　using　GeO2　and　ZnO　under　NH3　flow.　The　catalyst　was　used　as　a　visible-light　photocatalyst　for　the　decomposition　of　organic　compounds　in　polluted　water.　The　physicochemical　properties　of　the　synthesized　ZnGe　oxynitride　photocatalysts　were　characterized　by　several　techniques,　and　aqueous　photocatalytic　activity　was　evaluated　via　the　decomposition　of　model　organic　compounds　including　Rhodamine　B,　Methyl　orange,　Methylene　blue,　4-chlorophenol,　and　salicylic　acid.　The　results　demonstrate　that　ZnGe　oxynitride　can　photocatalytically　oxidize　organic　pollutants　in　aqueous　solution　under　visible　light　irradiation,　suffering　no　obvious　catalyst　deactivation　during　reaction　testing.　The　possible　active　species　in　the　photocatalytic　process　are　also　discussed.