ObjectiveTo get specific antigen epitope of B virus gC protein.MethodsSynthesis specific antigen epitope of B virus gC gene by using synthesis gene of Long fragment, cloned the gene into the pMAL-5x vector and transformed into E.coli BL21 to express and purify the expression product. ResultsWe get the B virus gC protein specific antigen protein successfully, and the protein expression in soluble form.ConclusionProkaryotic expression system can produce soluble B virus gC protein antigen and can be used as the detection of B virus antigen