Single Comb Brown Leghom male chicks were used to measure the effect of age of assay bird on true metabolizable energy (TME) value of corn, by 6 weeks interval from 8 to 26 weeks old, and were used to measure metabolic fecal and endogenous urinary energy (FEm+UEe) excreted from unfed birds at each age of birds. There were 7 replications. The results obtained are summarized as follows. 1. Gross energy values excreted from fed birds were significantly decreased (p$lt;0.05) as age of bird increased from 8 week to 14 week, although feed energy intakes as corn were almost similar in all ages of birds. 2. Metabolic fecal and endogenous urinary energy (FEm+UEe) values and nitrogen excreted per ㎏ body weight from unfed birds decreased as age of bird increased, but were similar between 20 and 26 weeks old birds. 3. The T M E value of corn in ㎉/g. of air dry matter was the lowest at 8 week old birds as 3.379±0.030 in compare with other ages of buds (p$lt;0.01), however, T M E values were similar among ages more than 14 weeks old. 4. The relationship between body weight(X) and gross energy(Y) excreted per ㎏ body weight of unfed birds was Y=10.607-2.798X (p$lt;0.01). 5. The mean THE value of corn was 3.468㎉(per g. air dry matter).