This study was performed to determine the effects of dietary Kocetin$^{TM}$ on meat quality of Hanwoo (Korean native cattle) beef. Samples were divided into 3 groups; dietary supplementation of Kocetin$^{TM}$ (KC) at 21 and 42 ppm (n=4), and non-supplemented control (n=3) for 75 days. The KC composed of 10% of quercetin which was a bioactive compound. After slaughtering the Hanwoo, each loin from 10 Hanwoos were obtained and analyzed. Dietary supplementation of KC did not affect the final pH, water holding capacity, drip loss, cooking loss, surface color, total phenolics content, radical scavenging activity, and sensory scores. Dietary quercetin also showed no difference in both TBARS and VBN values. Textural profile analysis results also showed no difference, except for adhesiveness and springness. Springness was significantly higher in loin from Hanwoo treated by dietary KC at 42 ppm when compared to control. Results revealed that the loin from Hanwoo fed dietary KC up to 42 ppm (approximately 4.2 ppm of quercetin) was not sufficient to have clear positive effects on meat quality of loin.