Abstract: Objective To express the white spot syndromevirus(WSSV)mimediate early prote in(IE1)in prokaryotic expression system,and to purify and identify the prote in expressed.Methods The encoding fragment of IE1 was inserted into plasmid pGEX-4T-2 and the recom binant plasmid pGEX-4T-2-IE1 was transformed into E.coli BL21 and induced by isopropy lD thiog alacto side(IPTG).The expressed glutathione Stran sferase(GST)IE1 was purified by affinity chromatog raphy column and identified by sodium dodecyl sulfate poly acrylamide gelelectropho resis(SDS-PAGE)and western blot.Results Anovel cDNA sequence encoding IE1 with amolecular mass of 25015.2,pI 4.87,which was 675bp and encoding 224 aminaacids,was obtained.The recom binant plasmid pGEX-4T-2-IE1 was constructed and expressed in fusion protein.Conclusion Recom binant GST-IE1 prote in was obtained and could be used in the functional study of IE1.