Lipoic acid synthase, which exists primarily in mitochondria, participates in the biosynthesis of intrinsic lipoic acid. The lipoic acid synthase gene in pig is known as LIAS. To further investigate the biological functions of the protein that is encoded by LIAS, we cloned the open read frame of porcine LIAS (GenBank No. JN797612.1) into the expression vector pET-28α(+). The resulting pET-28α(+)-Lias recombinant vector was introduced into the Escherichia coli BL21 (DE3) strain. With induction by isopropyl β-D-1-thiogalactopyranoside, the recombinant E. coli strain can express the target protein that has a molecular weight of 41.58 kDa, which was confirmed by Western blotting.