Adult single comb white Leghorn roosters were used to measure the effect of the level of feed input feeding methods as force feeding and intake restricted free feeding and on true metabolizable energy (TME) value of corn. The level of feed input as corn was ranged from 10g to 50g by 10g increments. Unfed birds were used to measure the FEm + UEe loss for each experiment. The results obtained were summarized as follows: 1. Gross energy voided as excreta from fed birds tended to increase in a linear manner as the intake of corn increased. 2. Mean metabolic fecal and endogenous urinary energy (FEm + UEe) and nitrogen excreted from unfed birds were 7.021±0.328 ㎉ (3.628 ㎉/㎏ BW/24hr.) and 0.4488 (0.232g/㎏ BW/24hr.), respectively. 3. The mean THE value of corn was 3.551 ㎉ (per g. of air dry basis) 4. Total gross energy intakes of force-feeding birds and free-feeding birds were 117.300 ㎉ and 112.217 ㎉ per bird. 5. Gloss energy excreted from force-feeding and free-feeding birds were 18.936 ㎉ per bird. 6. The THE value of corn was similar in force-feeding and free-feeding as 3.557 ㎉/g. and 3.549 ㎉/g., respectively. It was concluded that the THE value of corn was not affected by the level of feed input as corn and the optimum level of feed input as corn was 30-40g when the assay bird was an adult S.C.W.L. rooster. And the free-feeding method was more convenient than force-feeding method by eliminating difficult problem such as force-feeding.