An　effective　high　performance　liquid　chromatographic　method　has　been　developed　for　the　determination　of　dye　methylene　blue(MB)　and　its　metabolites　azure　A(　AZA)　,　azure　B　(　AZB　)　,　azure　C　(　AZC　)　in　aquatic　products,　and　applied　to　samples　of　incurred　samples,　which　had　been　dosed　with　methylene　blue.　Based　on　ion-pair　formation　with　p-toluenesulfonic　acid,　the　analytes　were　extracted　from　homogenised　tissue　using　acetonitrile,　partitioned　against　methylene　dichloride　,　and　purified　with　a　mixed-mode　cation　exchange　solid　phase　extraction　cartridges.　The　linear　range　was　0.　005　-0.　50　mg/kg　in　spiked　samples　and　the　correla-tion　coefficients　were　0.　9946　-0.　9978.　The　average　recoveries　and　the　relative　Standard　deviation　ranged　from　75.9%　to　93.2%　and　3.3%　to　11.9%,　respectively,　in　spiked　tissue　samples　at　concentration　Ievels　ranging　from　0.005　to　0.5　mg/kg　of　each　analytes.　The　limits　of　detection(　LOD)　of　AZA,　AZB,　AZC　and　MB　were　1.27,　0.98,　1.48　and　1.33　μg/kg,　respectively.　This　method　is　suitable　for　the　determination　of　methylene　blue　and　its　metabolites　residues　in　aquactic　products　and　pharmacokinetics　study.