Citrinin　(CIT)-protein　artificial　antigen　was　prepared　by　conjugating　CIT　with　keyhole　limpet　hemocyanin　by　1,4-butanediol　diglycidyl　ether.　By　immunization　and　fusion,　a　hybridoma　cell　line　named　K2-F3,　which　stably　secreted　the　monoclonal　antibody　(McAb)　against　CIT　was　obtained.　The　titer　of　the　CIT-　specific　McAbs　purified　by　affinity　chromatography　came　to　1:1.38×10　5.　The　indirect　competitive　enzyme-linked　immunosorbent　assay　(ELISA)　showed　that　the　detection　limit　of　CIT　was　0.01ng/mL,　with　a　good　linearity　ranging　from　0.01　to　1.0ng/mL.　The　McAb　was　highly　specific　and　cross-reactivity　rate　was　less　than　0.01%.　The　data　showed　that　the　ELISA　developed　could　accurately　determine　CIT　in　the　real　contaminated　red　yeast　rice　samples.　The　systematic　error　was　low　with　the　coefficient　of　variation　from　2.91　to　8.53%　by　the　ELISA.　PRACTICAL　APPLICATIONS:　CIT　is　a　toxic　fungal　metabolite.　It　often　occurs　in　naturally　contaminated　commodities,　such　as　in　corn,　barley,　wheat,　apple　and　some　foods.　CIT　is　hepatonephrotoxic　and　implicated　in　disease　outbreaks　in　animals　and　humans.　Nowadays,　food　security　problem　due　to　the　contamination　of　CIT　has　been　a　growing　concern　for　the　government　and　the　public,　especially　in　Asian　countries.　In　this　work,　a　high-specificity　McAb　against　citrinin　was　obtained.　The　indirect　competitive　ELISA　based　on　the　obtained　McAb　exhibited　a　high　sensitivity　and　precision.　The　detection　limit　of　CIT　was　0.01ng/mL.　The　indirect　competitive　ELISA　developed　could　determine　CIT　with　a　satisfactory　precision　for　the　real　red　yeast　rice　samples.　This　work　would　be　helpful　for　establishing　the　technology　and　developing　the　kit　to　determine　CIT-contaminated　samples　by　ELISA.　©　2011　Wiley　Periodicals,　Inc.