To produce male Muscovy only for fatty liver and meat-type production is an important economic goal in animal husbandry, although the sex-determining mechanism in poultry remains to be elucidated. Manipulation of sex-determining gene(s) in poultry provides enormous opportunities on the development of sex pre-selection reproductive systems. DSX and MAB-3 genes in Drosophila and C. elegans are conserved across the human, mice, chickens, fish, turtles, and reptiles revealing an ancient sex-determining locus DMRT1. Thus the Z-linked, DMRT1 in chicken is an excellent candidate regulatory gene controlling similar aspects of sexual development in poultry. This dissertation is aimed to clone and characterize Muscovy DMRT1 gene for further application in sex pre-selection. Partial cDNA sequences of Muscovy DMRT1 was determined and revealed 95% identity and 83% with chicken and red-eared slider turtle DMRT1 cDNA sequences. DMRT1 orthologs among various species were analyzed by Phylip program and phylogenetic tree was constructed by MEGA2 programs. Results indicated that Muscovy, chicken and red-eared slider turtle DMRT1 revealing 95%, and 83% identity at cDNA and 61%, 54% identity at amino acid level.