Electrochemiluminescent　(ECL)　behaviors　of　oxypurinol　in　alkaline　tris(2,2-bipyridine)ruthenium(II)　(Ru　(bpy)32　+)　solution　were　studied　in　a　flow　injection　electrochemiluminescent　system　(FI-ECL)　in　this　paper.　It　was　found　that　the　ECL　response　of　oxypurinol　was　significantly　pH-dependent.　It　inhibited　the　ECL　of　Ru　(bpy)32　+　at　≤pH　10.0,　whereas　exhibited　enhanced　ECL　response　at　pH　≥　11.0.　Additionally,　other　experimental　conditions　such　as　the　applied　potential　of　working　electrode,　the　flow　rate　of　carrier　solution,　and　the　concentration　of　Ru　(bpy)32　+　were　all　observed　to　affect　the　ECL　response　of　oxypurinol.　Under　the　optimum　conditions,　the　logarithm　of　enhanced　ECL　intensity,　ΔI,　was　found　linearly　proportional　to　the　logarithm　of　oxypurinol　concentration　in　the　range　of　1.0　×　10-7-1.0　×　10-4　mol　L-1,　and　the　detection　limit　(S/N　=　3)　was　3.0　×　10-9　mol　L-1.　The　mechanism　of　inhibited　and　enhanced　Ru　(bpy)32　+　ECL　by　oxypurinol　was　studied,　and　a　new　and　sensitive　flow　injection　analysis　(FIA)　method　basing　on　the　enhanced　ECL　was　proposed　for　detection　of　oxypurinol.　©　2006　Elsevier　B.V.　All　rights　reserved.