BST-2 is a new kind of antivirus protein that is induced by IFN α/β. The BST-2 gene fragment was amplified by RT-PCR from pig kidney cells (PK-15) and subcloned into the pLenti7.3/V5-TOPO vector and the positive clone was filtrated. The positive plasmids were transfected into the HEK293T cells. The expressed protein was analyzed by SDS-PAGE. Vesicular stomatitis virus (VSV)-CEF restrain experiment and Porcine reproductive and respiratory syndrome virus (PRRSV) intervence experiment were carried out. Results showed that the sequence of BST-2 gene amplified by RT-PCR was the same as the sequence in gene map of GenBank and its protein molecular weight was 23 kD, which was the same as the fusion protein V5-BST-2, and the recombinant BST-2 has obvious antiviral activity.