Abstract: Sj20.8 gene was amplified by PCR and inserted into eukaryotic expression plasmid pcDNA3.1 to construct recombinant plasmid pcDNA3.1/Sj20.8， which was then injected into the quadriceps femoris of the BALB/c mice. Results showed that the Sj20.8 antigen was low expressed in the local tissue of the mice， and was not able to significantly reduce eggs in the liver than in the control mice.

Key words: Schistosoma japonicum(Chinese strain), cDNA library, Gene, Sj20.8