White spot syndrome virus (WSSV) is the major pathogenic germs.It causes extensive mortalities in aquaculture.WSSV infection can bring about oxidative stress through the release of reactive oxygen species (ROS) which are deleterious to the cells (Mohankumar and Ramasamy, 2006).Peroxiredoxin (Prx) is known to be an antioxidant protein that protects the organisms against various oxidative stresses and functions in intracellular signal transduction (Ishii et al., 2012).A PrxⅣ (MjPrxⅣ) gene was cloned from from kuruma shrimp, Marsupenaeusjaponicus (M.japonicus).