Abstract: The phage display peptides libraries of Classic Swine fever virus （CSFV）E2 gene were constructed to identify the potential epitopes of E2 protein by biopanning. The E2 genes of Shimen strain (SM) and hog cholera lapinized virus (HCLV) strain were cloned into T7seclect415b vector respectively. So the E2 gene phage display peptides libraries of Shimen strain and HCLV strain were constructed and named as SME2 libraries and HCLVE2 libraries. CSFV polyclonal antibody(PcAB) and seven strains of McAbs were used to screen the epitopes in SME2 libraries and HCLVE2 libraries by biopanning and phage in situ hybridization. After analyzing the sequences of selected phage recombinants, five sequences which were highly homologous with TAVSPTTLR, YYEP, TTWKEYSH, GGQ（V）VK and PDGLPHY were selected by the MAbs and CSFV PcAB. These results proved that these three sequences of TAVSPTTLR, YYEP and TTWKEYSH are dominant epitopes on E2 protein, which were reported in the previous papers. In addition, two sequences of GGQ（V）VK and PDGLPHY corresponds to the epitopes predicted by computer. So these two sequences might be the potential epitopes of E2 protein.