The cDNA encoding gonadotropin-releasing hormone(GnRH) and GnRH associated peptide(GAP) was amplified from total RNA from Oreochromis aurea pituitary glands by reverse transcription polymerase chain reaction(RT-PCR) method,and then blasted against other GnRH cDNA sequences in the GenBank.The analysis of the sequence data indicated that the coding region of the cDNA fragment,which encoded 89 amino acid redidues,is about 400 bp in size.A high homology was found with the GnRH coding region within O.niloticus,O.aurea and S.aurata.The amplified cDNA fragment was cloned into the prokaryotic expression vector,pMAL-c2x,to produce the expression vector pMAL-GnRH.The recombinant plasmid was transformed into E.coli TB1.GnRH-MBP fusion protein was obtained after the addition of IPTG into the growth media.SDS-PAGE analysis revealed that the GnRH-MBP was expressed after induction with IPTG for 4h.A protein band of 56 kD appeared on SDS-PAGE gel.It is anticipated that the fusion protein will be proved useful for further research.