The objective of present research is to evaluate the effect of breed and sex on flavor-related compounds of duck meat in Korea. Breast meat of each different breed [Korean native duck (KND) and commercial duck, Cherry Valley (CD)] and sex (male and female) were analyzed for chemical composition, nucleotide, fatty acid composition, and free amino acid. In comparison within the different breed and sex, CD and female duck were higher in moisture composition compared to KND and male duck. The meat from female duck had higher inosine monophosphate (IMP) contents while the meat from KND had higher inosine contents (P<0.05). Mostly, male duck had higher contents of free amino acid, including alanine, aspartic acid, glycine, histidine, leucine, serine, valine, glutamic acid and cysteine (P<0.05), even though no significance in the sum of taste-related free amino acid was observed with respect to breed and sex. From the results, it was found that breed has no significant impact while sex has influenced the flavor-related compounds, especially, IMP and most of the free amino acids. In order to get breed-specific advantages, KND should be developed based on flavor aspect and further studies using KND with known genetic confirmation should be conducted for the extrinsic and intrinsic flavor influencing factors.