According to three active T lymphocyte epitopes (TCE) which Stevenson screened, tce gene (180 bp) was synthesized and cloned successfully into pMD18-T Simple vector. tce gene was subcloned into prokaryotic expression vector pET-32a(+); the recombinant plasmid was named pET-TCE and induced by IPTG. The results of SDS-PAGE and Western-blot indicated that the tce gene was expressed at a high level, and the recombinant fusion protein was about 25 000. The recombinant fusion protein has a peculiar reaction to porcine circovirus 2 (PCV2) positive serum which has immunological activity.