Porcine circovirus type2 represents the causative agent of a new porcine disease which spread in form of an epidemic all over the world in the past years. In the previous studies demonstrated that the ORF2-encoded structure protein of PCV2 was associated with neutralizing epitopes. But the functions of ORF3-encoded protein of PCV2 is unknow now. The purpose of the this study is to investigate the ability of ORF2- and OFR3-encoded protein of PCV2 to elict the neutralizing antibodies in host by means of expressed protein immunization and DNA immunization. The viral DNA was extracted from Taiwanese PCV2, ORF2- and ORF3-encoding region was amplified by PCR. The PCR product was inserted into the pRSET vector. The BL21 (DE3) cell was transfected with pRSET-ORF2 and pRSET-ORF3 plasmid. The ORF2 and ORF3 recombinant protein was expressed after IPTG inducing and detected with anti-PCV2 polyclonal antibody by Western blotting. Then, the intraperitoneal injection of recombinant protein into BALB/c mice was performed. Serum samples were collected and checked for ORF2- and ORF3-specific neutralizing antibodies by virus neutralization test.