Tachaea chinensis is a parasitic isopod that negatively affects the production of several commercially important shrimp species in China. However, shrimp host antioxidant and immune responses and underlying molecular mechanisms during the course of isopod parasite infection have not been reported. In this study, the speci?c activities of immune and antioxidant enzymes of Macrobrachium nipponense during the 15 days infection course and its related genes expressed were evaluated.