In order to investigate an utilizability of citrus pulp, a byproduct of manufacturing juice or can from orange, as a possible feed resource, metabolizable energy (MEn) and productive energy (PE) of untreated citrus pulp were compared with those of wheat bran and citrus pulp extracted with acetone (citrus pulp-AE) or ultrasonically treated citrus pulp (citrus pulp-UT). Hatched single comb White Leghorn male chicken were raised for 8 days with a commercial diet and for next 3 days with basal (wheat bran) diet and for subsequent 10 days with experimental diets containing 17.0% of cellulose (cotton meal), wheat bran, untreated citrus pulp, citrus pulp-AE arid citrus pulp-UT, respectively. The MEn was measured by intake energy minus excreted energy in excreta and the PE was calculated by protein and lipid retention determined by carcass analysis of birds. Body weight gain or protein and lipid retention were not significantly different among buds fed experimental diets. But the body weight gain or protein and lipid retention of birds fed citrus pulp-AE and -UT were highering compared with that fed untreated citrus pulp, And feed conversions of birds fed citrus pulp-AE and -UT showed lowering tendency compared to that fed untreated citrus pulp. The rate of MEn to gross energy (GE), MEn/GE, was not significantly different between birds fed wheat bran diet and those fed citrus pulp-AE and -UT diets, which were higher than that fed untreated citrus pulp. But PE and PE/MEn were not significantly different among birds fed experimental diets.. MEn of citrus pulp-AE had shown 1.885 ㎉ per gram dry matter was similar with that of wheat bran, which was significantly higher than those of untreated citrus pulp and citrus pulp-UT. The MEn/GE of citrus pulp-AE had been 44.8% and was also similar with 43.2% oi` wheat bran, which was significantly higher than 21.8 and 29.1% of untreated citrus pulp and citrus pulp-UT, respectively. The PE of untreated citrus pulp, citrus pulp-AE and citrus pulp-UT reached to 0.906, 1.831 and 1.500 ㎉ per gram dry matter, respectively. The results seem to indicate that the energy utilization of citrus pulp extracted with acetone be similar with that of wheat bran and that the availability of citrus pulp would be improved by some proper treatment.