The purpose of this study was to investigate changes of plasma epinephrine and lactate during maximal exercise in various glycogen conditions. The subjects were composed of 7 male college students. They performed the incremental exercise test by way of bicycle ergometer in normal glycogen condition, glycogen-depleted condition and glycogen-loaded condition. Glycogen depletion and loading were formed as a result of exercise and dietary. Plasma epinephrine and lactate were analyzed from blood samples extracted from the antecubital vein every 3 minutes until exhaution. On the basis of the results analyzed in this study, conclusions were drawn as follows: 1. Plasma epinephrine in glycogen-loaded condition markedly increased with workloads, and the difference of epinephrine concentration between glycogen loaded condition and glycogen-depleted condition was significant(p<0.05) from 120 watt workload upward. 2. Lactate concentration remarkably increased in glycogen-loaded condition with workloads, and differences among three conditions were significant(p<0.01) at lower workloads. 3. Changes of epinephrine and lactate were similar in all conditions. But changing points of these variables were occurred at lower workloads and higher workloads in glycogen-loaded condition and glycogen-depleted condition, respectively.