To investigate the role of chondroitin sulfate N-acetylgalactosaminyltransferase-1（CSGalNAcT-1） played in the immune response of Procambarus clarkii，in this study，the complete cDNA sequence of the P. clarkii CSGalNAcT-1 was obtained by RACE，and its expression patterns in response to stimulation of CpG oligodeoxynucleotide（ODN），Aeromonas hydrophila and white spot syndrome virus（WSSV） were investigated by real-time PCR.The results indicated that the relative expression of CSGalNAcT-1 was highest in the midgut，followed by the foregut，and less in the heart，stomach，muscle and periesophageal nerve in P. clarkii.Besides，the expression of CSGalNAcT-1 in the hepatopancreas and haemocytes which were considered as immune organs of crustacean，could be down-regulated and up-regulated by challenges of A. hydrophila and WSSV，respectively，and the expression was up-regulated in most of the tissues after injected with CpG ODN，indicating that the CSGalNAcT-1 gene may play an important role in resisting the pathogenic infection and enhancing the autoimmune response in P. clarkii.