Glutathione S-transferases (GSTs) are a family of multifunctional enzymes,belonging to a group of xenobiotic metabolizing phase Ⅱ detoxification enzymes.The main function of GSTs is achieved by the nucleophilic attack of the glutathione sulfur to electrophilic substrates of endogenous or foreign toxic substances,resulting in depending on the hydrophobic substrate and easy to export from animal cells.In order to clarify the relationship between GSTs enzyme and AFB 1 toxic effect in crustacean,a Delta-class GST gene was cloned from the hepatopancreas of the black tiger shrimp,Penaeus monodon and named PmDeltaGST.