Abstract: Porcine circovirus typeⅡ(PCV2) plays a crucial role in the pathogenesis of post-weaning multisystemic wasting syndrome(PMWS) in swine. The truncated ORF2 gene of PCV2 was amplified by PCR and the PCR product was cloned into plasmid PGEX-6P-1. the recombinant plasmid was name PGEX-ORF2. The PGEX-ORF2 was transformed into E.coli BL21(DE3) cells, and induced by IPTG at 37℃ for 4 hours. The recombinant PCV2 Cap protein was expressed efficiently in the form of inclusion body. SDS-PAGE and Western blotting analysis showed that the recombinant fusion protein had a molecular weight of approximate 46 kD, and had immunological reactivity.