Abstract: The five monoclonal antibodies (mAbs) against classical swine fever virus were generated by immunization of BALB/c mice respectively with CSFV DNA vaccine plasmid (expressing glycoprotein E2) and E.coli-expressed E2 protein. These mAbs could react with CSFV growing in PK-15 cells in indirect immunofluorescent assay (IFA), as well as with expressed E2 protein in western-blotting. Of them, the mAbs 1E2, 3B7 and 4B6 are CSFV specific antibody without cross reaction with E2 protein of BVDV, therefore have been used, along with rabbit anti-CSFV IgG, to develop the antigen-captured ELISA(AC-ELISA) for detecting CSFV antigen directly from clinical tissue samples. The cut-off value was determined by testing negative tissue samples of 24 healthy pigs. The method was testified by comparison with virus isolation and RT-PCR of 31 positive tissue samples from piglets experimentally infected with CSFV shimen strain,11 clinically CSF cases and 12 healthy samples. The results showed that the AC-ELISA is sensitive, specific and has high consistency with virus isolation and RT-PCR.