Electrochemiluminescent　(ECL)　behaviors　of　oxypurinol　in　alkaline　tris(2,2-bipyridine)ruthenium(II)　(Ru(bpy)(2+)(3)　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)(2+)(3)　at　＜=　pH　10.0,　whereas　exhibited　enhanced　ECL　response　at　pH　＞=　11.0.　3　Additionally,　other　experimental　conditions　such　as　the　applied　potential　of　working　electrode,　the　flow　rate　of　carrier　solution,　and　the　concentration　of　Ru(bpy)(2+)(3)　were　all　observed　to　affect　the　ECL　response　of　oxypurinol.　Under　the　optimum　conditions,　the　logarithm　of　3　enhanced　ECL　intensity,　AL　was　found　linearly　proportional　to　the　logarithm　of　oxypurinol　concentration　in　the　range　of　1.0　X　10(-7)-　1.0　X　10(-4)　mol　L-1,　and　the　detection　limit　(S/　=　3)　was　3.0　x　10(-9)　mol　L-1.　The　mechanism　of　inhibited　and　enhanced　Ru(bpy)(2+)(3)　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.　(C)　2006　Elsevier　B.V.　All　rights　reserved.