본 연구는 근육 부위 및 숙성이 한우 경산우육의 유리 아미노산 및 향기 성분에 미치는 영향을 구명하고자 실시하였다. 시료의 처리는 101개월령 한우 경산우들의 등심(M. longissimus)과 우둔(M. semitendinosus)을 2℃에서 14일 동안 숙성하였다. 유리 아미노산은 숙성 14일째 등심과 우둔 모두에서 증가하였으며, asparagine, glutamine, histidine, glycine, threonine, arginine, tyrosine, phenylalanine, isoleucine, leucine, lysine에서 등심이 우둔보다 높았다 (p<0.05). 특히 glutamine의 경우 약 4~6배로 가장 높았다. 휘발성 향기 성분은 다양한 알데하이드류, 케톤류, 알코올류, 탄화수소류, 질소 및 황화합물이 등심과 우둔에서 검출되었으며, 다수의 성분들이 숙성 14일째 증가하는 경향을 보였다. 또한 등심에서는 14종의 알데하이드류(acetaldehyde, 2-methylpropanal, 3-methylbutanal, 2-methylbutanal, pentanal, hexanal, heptanal, E-2-heptanal, octanal, 2-octenal, 2-nonenal, E-2-decenal, E,E-2,4-decadienal, 2-undecenal), 5종의 케톤류(2-propanone, 2,3-butanedione, 2-butanone, 2-heptanone, 2,3-octanedione), 4종의 알코올류(ethanol, 1-pentanol, 1-hexanol, 1-octanol), 3종의 탄화수소류(3-ethyl-2-methyl-1,3-hexadiene, 3-methyldecane, 2,2-dimethyloctane)에서 우둔에 비해 현저하게 높았다(p<0.05). 반면에 우둔에서는 5종의 질소 및 황화합물(methanethiol, dimethyldisulfide, fufuralll, 2,5-dimethylpyrazine, 2-octylfuran)이 등심에 비해 현저하게 높았다(p<0.05).This study was carried out to investigate the effect of muscle part and aging period on free amino acids and aroma compounds of Hanwoo (Korean cattle) cow beef. The M. longissimus (ML) and M. semitendinosus (MS) from 101 mon-old-cows were aged at 2℃ for 14 d. The free amino acids concentration increased in both ML and MS on 14 d of aging. In ML, asparagine, glutamine, histidine, glycine, threonine, arginine, tyrosine, phenylalanine, isoleucine, leucine and lysine were significantly (p<0.05) higher than those in MS. Varieties of aldehydes, ketones, alcohols, hydrocarbons, nitrogen and sulfur compounds were detected in both ML and MS and majority of these compounds showed increasing trend on aging. The ML had higher 14 aldehydes (acetaldehyde, 2-methylpropanal, 3-methylbutanal, 2-ethylbutanal, pentanal, hexanal, heptanal, E-2-heptanal, octanal, 2-octenal, 2-nonenal, E-2-decenal, E,E-2,4-decadienal and 2-undecenal), 5 ketones (2-propanone, 2,3-butanedione, 2-butanone, 2-heptanone and 2,3-octanedione), 4 alcohols (ethanol, 1-pentanol, 1-hexanol and 1-octanol), 3 hydrocarbons (3-ethyl-2-methyl-1,3-hexadiene, 3-methyldecane and 2,2-dimethyloctane) significantly (p<0.05) compared with MS. However, the MS had higher 5 nitrogen and sulfur compounds (methanethiol, dimethyldisulfide, fufural, 2,5-dimethylpyrazine and 2-octylfuran) significantly (p<0.05) compared with ML.