Fifty four Hanwoo steers in final fattening period were assigned to 3 groups control, top dressed $PROSOL^{(R)}$ as an emulsifier (TP) and DSP group (experimental diet made to down spec of nutrients with $PROSOL^{(R)}$, which is sodium stearoyl-2-lactylate), based on the body weight (647.96${pm}$41.31 kg) and months of age (27.3${pm}$0.8 mo), and the experiment was conducted to establish the reasonable fattening method of Hanwoo steers for 91 days. Average daily body gains during trial were 0.94, 0.84 and 0.98 kg in control, TP and DSP, respectively (P=0.011). DDMI/ADG of TP group tend to lightly improving compared to control and DSP group (P=0.692). There was no effect of supplementation of the $PROSOL^{(R)}$ in concentrates on growth rate, feed efficiency and shrinkage in Hanwoo steers during the short final fattening period. MQI from TP and DSP was not different based on the rib-eye area and carcass weight in carcass than that from control. Back fat thickness tended to be thicker than control (P>0.05). Marbling score, texture and maturity for TP and DSP was abundantly to increase compared to control (P<0.003). There was significantly increment in supplemented $PROSOL^{(R)}$ (P<0.0001). The meat quality grade of control, TP and DSP were 2.94, 3.78 and 4.50, respectively. Related to this result, the auction price (carcass/kg) were gained significantly (P<0.003) from control (17,560), TP (18,586) and DSP (19,266 won) so which the monetary return was the highest in DSP and the differences was recognized between TP and DSP. Percentage over 1st grade appeared in control, TP and DSP were 55.4, 88.9 and 100.0%, respectively. These results supported the hypothesis that supplementation of emulsifier improve the marbling score and the carcass quality grade by increased digestibilities of the feed fat in Hanwoo steers in fattening period.