The effects of hexestrol dicaprylate (HESC) implantation on rate of gain and economic feed utilization were studied. Ten Korean native yearling bulls and a corresponding number of controls were used in this experiment. All animals were fed a fattening ration of soiling corn and concentrate made up of 50% corn, 48% brans and 2% others for 105 days. Implanting with 100㎎ of HESC increased rate of gain by 0.6%. Feed required per 1㎏ of gain was decreased by the implanting of HESC. Implanting with HESC increased rate of nutrient utilization for 1㎏ of body gain by 6.6% DCP and 6.9% TDN. No undesirable effects was noted in the experiment.