Abstract: 　AIM: To observe the anti fecundity effect of recombinant Sjc26 GST against Schistosoma japonicum and its mechanism.METHODS:Male ICR mice were immunized with rSjc26 GST.Five days after final injection, mice of the immunization and control groups were challenged with 40±1 S.japonicum cercariae . All mice were sacrificed at 6 weeks after challenge.RESULTS: The worm reduction rate was 30 0%,and the egg reduction rates in the liver and in the spleen were 57 1% and 79 9%, respectively. Inhibition of the vitelline gland and testis was also observed by transmission electron microscopy. The number of vitelline globes, vitelline droplets and lipid droplets in the cytoplasm of vitelline cell and the number of lipid droplets in the supporting cells and the number of spermatids in the testis were apparently reduced.CONCLUSION:The damage of the main reproductive organs of Schistosoma japonicum was one of the factors responsible for rSjc26 GST bound anti fecundity action.

Key words: Schistosoma japonicum, recombinant Sjc26 GST, immune, anti fecundity action