This study was conducted to investigate the effects of feeding DDGS and full-fat soybean in the finishing diet on the performance, carcass characteristics and unsaturated fatty acid composition of Hanwoo steers. Thirty Hanwoo steers (average age, 26.4 months; weight, 756.69 kg) were assigned into Control (no additive), DS (DDGS supplemented) and FS (full-fat soybean supplemented). The feeding rate of DDGS and full-fat soybean was set at 10% and 5% in the finishing diet, respectively, and the in vivo trial was conducted for 122 days. The final body weight was 779.81, 774.20 and 791.95 kg for Control, DS and FS, respectively, and the average daily gain was not different among treatments. The feed conversion ratio was lower in FS compared to Control. Carcass cold carcass weight, backfat thickness, M. longissimus dorsi area and marbling scores were not different among treatments, and moisture, crude protein, and crude fat content in carcass were not different. The melting point of sirloin ranged from 25 to 26℃ among treatments. The saturated fatty acid, C18:0, was lower in the FS than in Control. C18:1, the main unsaturated fatty acid (UFA) in carcasses, did not show any difference among treatments, but C18:2 was higher in DS than in Control. Total UFAs were higher in the FS than in Control. Based on the above results, DDGS feeding was effective in improving feed conversion ratio and C18:2 content, and full-fat soybean feeding was effective in improving feed conversion ratio and increasing UFA content.