A　novel　technology　to　determine　the　concentration　of　xanthine　through　the　chromogenic　reaction　of　phenic　acid(PA),　4-aminoantipyrine　(AAP)　and　hydrogen　peroxide　(H2O2),　which　was　produced　via　the　oxidation　of　xanthine　catalyzed　by　xanthine　oxidase　(XO),　under　the　help　of　horseradish　peroxidase　(HRP)　was　proposed　in　this　paper.　The　influences　of　temperature　and　pH　on　the　system　were　investigated.　The　optimal　conditions　to　determine　the　concentration　of　xanthine　were　obtained　as　follows:　XO(0.32　U/mL),　HRP(7.0U/mL),　4-aminoantipyrine(1mmol/L),　and　phenic　acid　(6mmol/L)　were　dissolved　in　100mmol/L　Tris-HCl　buffer　solution(pH　8.4),　the　reaction　system　was　incubated　in　thermostat　of　37°C　for　20min,　the　absorptive　wave　was　508nm.　Under　the　conditions　mentioned　above,　the　linear　range　of　calibration　curve　was　between　0.2mmol/L　and　10.0mmol/L,　the　correlation　coefficient　was　0.9978,　and　the　limit　of　detection　was　0.05mmol/L.　All　these　show　this　technology　is　a　potential　alternative　method　to　determine　the　concentration　of　xanthine　in　the　areas　like　for　example　in　laboratory　or　clinical　diagnosis.