Based　on　the　strong　electrochemiluminescence　(ECL)　reaction　between　thiamazole　and　tris(2,2-bipyridine)ruthenium(II)　(Ru(bpy)(3)(2+)),　a　sensitive,　simple　and　rapid　flow　injection　analysis　method　for　the　determination　of　thiamazole　was　developed.　When　a　Pt　working　electrode　was　maintained　at　a　potential　of　+1.50V　(vs　Ag/AgCl)　in　pH12.0　H3PO4-NaOH　solution　containing　thiamazole　and　Ru(bpy)(3)(2+)　at　a　flow　rate　of　1.0mL/min,　a　linear　range　of　2.0x10(-7)-1.0x10(-4)mol/L　with　a　detection　limit　of　5.0x10(-8)mol/L　was　obtained　for　the　detection　of　thiamazole.　The　method　showed　good　reproducibility　with　a　relative　standard　deviation　(RSD)　of　0.75%.　The　method　has　been　successfully　applied　to　the　determination　of　thiamazole　in　spiked　animal　feeds.　In　addition,　a　co-reactant　ECL　mechanism　was　proposed　for　the　thiamazole-Ru(bpy)(3)(2+)　system.　Copyright　(c)　2014　John　Wiley　&　Sons,　Ltd.