This experiment was carried out to investigate the effect of energy levels on performance and energy requirements of Korean native steers. Twelve Korean native steers initially averaging 200㎏ were allotted randomly into treatments. Experimental period was divided into three stages such as 200 to 250㎏ for period 1, 250 to 350㎏ for period 2 and 350 to 450㎏ for period 3. Three energy levels (2.4, 2.6 and 2.8Mcal/㎏ of diet) were employed for each period and protein content of diet was isonitrogenous to all energy levels, that is, 12% for period 1, 11% for period 2 and 10% for period 3. The results obtained were as follows. Total body gain was not significantly different from each energy level but daily body gain was significantly (P$lt;0.05) higher in steers fed 2.6Mcal energy level than in steers fed 2.4 and 2.8Mcal energy levels. Total and daily feed intake were significantly (P$lt; 0.05) higher in steers receiving 2.4Mca1 energy level compared with 2.6 and 2.8Mcal energy levels. Overall feed efficiency was greatly (P$lt;0.01) improved in steers receiving 2.6 and 2.8Mcal energy levels. as compared with in steers fed 2.4Mcal energy level. Total energy intake was much lower in steers fed 2.4 and 2.6Mcal energy levels than in steers fed 2.8Mcal energy level. However, daily energy intake was not different from each energy level. Ratio of feed to body weight was decreased by 0.2 or 0.3% when body weight increased by 50㎏ between 200 and 450㎏. ME required for ㎏ body gain was 17.25Mcal in steers fed 2.6Mcal energy level and lower than in steers fed 2.4 and 2.8Mcal energy levels. Therefore, it can be concluded that 2.6Mcal energy level was adequate to support maximum performance for Korean native steers averaging 200 to 450㎏ body weight.