Seventy two Hanwoo steers in final fattening period (585.87±41.02kg) were randomly assigned to 3 groups, LPLT (relatively low protein and low energy; CP 12%, TDN 73%), LPHT (relatively low protein and high energy; CP 12%, TDN 75%) and HPHT (relatively high protein and high energy; CP 14%, TDN 75%) in concentrate feed for 163 days in order to investigate the effects on growth performance, carcass characteristics, and longissimus dorsi muscle's chemical compositions. Rice straw was also fed as a roughage. Because ADGs were higher in LPLT and HPHT than LPHT, feed efficiencies were improved in LPLT and HPHT group (P<0.05). Feeding concentrates with different CP and TDN levels had affected to improve back fat thickness and rib eye area in HPHT group but had no effect on carcass weight and meat yield index. Carcass weight for LPLT, LPHT and HPHT were 420.75±30.56, 417.05±32.03 and 418.32±32.03 kg, respectively. Meat quality grade was improved in HPHT (P<0.001), because the marbling score was highest in HPHT group. Auction prices (carcass/kg) of LPLT, LPHT and HPHT group were 17,904 won, 18,094 won and 18,899 won, respectively. The percentage of animals over grade 1 appeared in LPLT, LPHT and HPHT were 79.2, 72.7 and 90.8%, respectively. The results of chemical analysis of longissimus dorsi muscle showed no difference between groups but crude fat composition tended to be higher in HPHT group (P=0.088) than the other groups. Stearic acid contents in the muscle was significantly increased in HPHT group than LPLT group (P<0.05). Myristoleic acid and oleic acid composition in HPHT group was higher than LPLT and LPHT group. These results supported the hypothesis that supplementation of higher levels of crude protein and energy in concentrates to Hanwoo steers' during final fattening period improved the growth performance and the carcass quality grade.