Human Clonorchis sinensis infection is endemic in East Asian countries. Glutathione S-transferases (GSTs) are anti-oxidant enzymes found in all living creatures as well as in trematodes. In this study, we examined the recombinant 26kDa GST protein of C. sinensis (Cs26GST) for its serodiagnostic antigenicity toward IgG and IgE antibodies by ELISA and immuno-enhanced chemiluminescence, respectively. In IgG ELISA, recombinant Cs26GST showed 33.3% sensitivity and 100% specificity for trematode-infected human sera. In the case of the IgE antibody, recombinant Cs26GST showed 50.0% sensitivity and 93.2% specificity for clonorchiasis infection. We propose that the recombinant Cs26GST is a potent serodiagnostic antigen for detecting C. sinensis-specific IgG and IgE antibodies, and that it be best used as an antigenic cocktail in combination with other antigens.