Abstract: Suppressors of cytokine signaling(SOCS)is an important inhibitor of JAK/STAT signaling pathway,which plays an important role in immunity,growth and development.The results of our previous transcriptome showed that the expression profile of Lv-SOCS fluctuated significantly in response to WSSV infection.It is suggested that Lv-SOCS might be involved in innate immunity in L.vannamei in response to WSSV infection.In this research,the full length cDNA of SOCS gene(Lv-SOCS,GenBank accession number:KJ000426)was cloned from hemocytes of L.vannamei.Lv-SOCS has a 1 191 bp ORF encoding 397 aa with a predicted molecular weight of 42.30 ku and calculated isoelectric point of 8.62.The SMART online software analysis shows that Lv-SOCS has two functional domains(SH2 domain and SOCS-box).According to the multiple sequence alignment,Lv-SOCS shows the highest similarity with Marsupenaeus japonicas SOCS which is in a same branch of phylogenetic tree with Lv-SOCS.Semi-quantitative RT-PCR revealed that Lv-SOCS was mainly expressed in hemocytes,intestine and hepatopancreas.The expression of Lv-SOCS could be up-regulated significantly after WSSV infection.The above results give important clues for further study on the function and regulation mechanism of Lv-SOCS in anti-WSSV immune response.