A cDNA fragment encoding mature salmon growth hormone (sGH) was successfully amplified by polymerase chain reaction and the restriction recognition sequences were respectively introduced into the 5' end and 3' end of the amplified fragment. The recombinant secretion vector pOsGH153 containing genes coding for the E.coli ompA signal peptide and mature sGH was constructed and confirmed by restriction enzyme analysis and Southern blot hybridization with the oligonucleotide probe. Upon induction of IPTG, the sGH was expressed in E.coli cells and was secreted into the E.coli periplasma.