Photocatalysis　is　a　promising　way　to　eliminate　organic　pollution.　Here　a　novel　homogenous　non-oxygen　photocatalytic　system　was　studied.　Acetic　acid　was　used　as　a　model　substrate　to　be　decomposed　into　hydrogen,　methane,　ethane　and　carbon　dioxide　continuously　by　photo-excited　Fe2+　and　Fe3+　ions.　Fluorescence　spectra　and　ultraviolet　visible　spectra　showed　that　Fe2+　and　Fe3+　were　excited　by　ultraviolet　light.　The　rate　of　acetic　acid　decomposition　increased　along　with　the　increase　of　temperature.　Fe2+　and　acetic　acid　concentration.　The　photocatalytic　mechanism　and　kinetics　were　proposed　and　the　effects　of　pH　value,　reaction　temperature,　concentration　of　FeSO4　and　CH3COOH　were　investigated.　(C)　2010　Elsevier　B.V.　All　rights　reserved.