High molecular weight DNA was isolated from porcine pituitary gland, and a genomic library was constructed using lambda EMBL3 as cloning vector. Five positive clones were identified by in-situ hybridization with the full-length pGH cDNA as the probe. Dot-blot hybridization, restriction analysis, and Southern hybridization showed that one of the positive clones contained the entire pGH gene. A subclone that contained the upstream sequence from the SmaI site of pGH gene was identified, and part of it was sequenced. We also compared the sequence of our pGH gene with the corresponding sequence of the published pGH gene.