Abstract: Objective To obtain genes encoding the novel molecules for diagnosis of schistosomiasis. Methods Juvenile S. japonicum cDNA library was immunoscreened to obtain positive clones. By DNA sequencing and sequence analysis， the target gene was amplified by PCR and subcloned into prokaryotic plasmid pET28a. The recombinant plasmid was transformed into E. coli BL21 followed by expression of the protein induced by IPTG. The protein was identified by Western blotting. Results 34 positive clones were obtained， 24 of which were chosen to be sequenced， 13 of which were Sj22600 gene. The protein were recognized with sera of infected rabbits and patients with acute and chronic schistosomiasis by Western blotting. Conclusion The gene coding for Sj22600 membrane protein was screened with high frequency in the cDNA library. The E. coli BL21 transformed with the recombinant plasmid can express the fusion protein，which shows immunoactivity.

Key words: Schistosoma japonicum, Schistosomulum, cDNA library, Immunoscreening, Sj22.6