Abstract: Interleukin-15 (IL-15) is a multi-functional cytokine of IL-2-like cytokine family and exerts profound effects on the proliferation and differentiation of lymphocytes and NK cells and the secretion of immunoglobulin. In this study, the porcine IL-15 (pIL-15) full-length gene was cloned from porcine peripheral blood molecular cells (PBMCs) using RT-PCR and ligated into pMD18-T vector Sequence analysis showed that the cDNA of pIL-15 is 486 base pairs in length and encodes a protein consisting of 162 amino acid (aa). The gene of mature pIL-15,which was deleting a 48 aa leader sequence at N-terminus,was cloned by PCR and then was introduced into downstream of 6 His of pET-28a, resulting in the prokaryotic expression plasmid pET-pIL15. After transforming into E．coli BL21 (DE3) and inducing by IPTG, the results of SDS-PAGE showed that the 6×His-pIL15 fusion protein about 15ku was acquired. Gel scanning analysis.revealed expression quantity of the fusion expression in all tropina was 17.5%. The result of Western blot demonstrated that the recombinant fusion protein 6 His-pIL15 can be recognized by anti-6 His monoclonal antibody. The cloning and expression of pIL-15 made a foundation for the study of function and application.