Abstract: Gonadotropin-releasing hormone (GnRH) is a conserved nerval decapeptidethat regulates the development and maintenance of reproductive function in vertebrate1The cDNA encoding the His5Trp7Tyr8 gonadotropin-releasing hormone ( chicken-?type GnRH, cGnRH-II) precursor from the brain of rice field eel ( Monopterus albus) has been isolated and sequenced by using reverse transcription and rapid amplification of cDNA ends ( RACE) 1From the subcloning and sequence analysis of 3c-RACE and 5c-RACE product, the complete sequence of the cDNA encoding its cGnRH-II peptide was identified and determined to be 617 bp in length1The structure of the encoded peptide is identical to all other cGnRH-II reported to date. The deduced peptide is composed of a signal peptide (SP), a GnRH decapeptide and a GnRH-associated peptide ( GAP) which is connected to GnRH by a Gly-Lys-Arg sequence1The cGnRH-II cDNA encoded SP of 21 amino acids and GAP of 49 amino acids. The amino acid sequence of cGnRH-II in combining with the Gly-Lys-Arg sequence is highly conserved during evolution when compared with the corresponding regions of other GnRH precursors. However, the untranslated region of GnRH are markedly divergent in nucleotide sequences