AIM: To investigate the adjuvant effect and protective activity of Schistosoma japonicum ribosome preparation (SRP). METHODS: Mice were immunized with SRP, SWA and SRP+SWA, respectively. Humoral immunity levels of mice were detected by ELISA and protective immunity of mice were indicated by worm reduction rate. RESULTS: Mice immunized with SRP or SRP + SWA produced higher specific antibody titer than mice immunized with SWA. However, mice immunized with SRP or SRP+ SWA failed to exhibit higher worm reduction rate than mice immunized with SWA. CONCLUSION: SRP could enhance the humoral response of mice to SWA, but did not result in protective immunity of mice against the schistosomes.