Abstract: In this article, the IgG was purified from the positive antiserum to FMDV-NSP 3ABC. The IgG was used as target molecule to screen the phage display 12mer random peptide library for 4 rounds by the binding-eluting-amplification method. After 4 rounds of screening, 20 clones were picked out randomly and amplified.Their antigenicities were tested by ELISA. Among 20 phage clones, 8 phage clones had specific reactions with the purified IgG.The ssDNA of the positive clones were abstracted for DNA sequencing and the sequences of peptides displayed on the positive clones were analyzed by ExPASy method.The results showed that the peptides displayed on the 7 phage clones were highly homologous. 22 dubitable porcine sera were tested by 8 positive clones which were used as target molecules respectively, and 5 clones showed high correlation with traditional Kit. These results were successfully provided a foundation for research of the structural epitope of the FMDV-NSP 3ABC and to establish a new diagnostic method for the natural infection of the FMDV.