RT- PCR and RACE( rapid amplification cDNA ends ) were used for the isolation of the full length cDNA of DMO gene from ovary of Oreochromis aurea. Sequence analysis revealed a 1571 bp cDNA containing the 148 bp 5.- untranslated region, 193 bp 3.- untranslated region and 1230 bp open reading frame encoding 409 amino acid. Sequence analy sis revealed the identity rate of deduced amino acid of DMO in O. aurea and O. niloticus is 96. 3%, which showed high homology in species. However, we compared the alignment of deduced amino acid sequences between DMO cDNA from O. aurea and DMRT1 cDNA from O. niloticus , fugu, rainbow tro ut, medaka, rat and human. The score was 25. 7%, 25. 8%, 24. 3%, 29. 7%, 22. 5% and 22. 0%, respectively. These results indicated that DMO and DMRT1 gene may be different genes.