It has been well recognized that many enzymatic chain reactions and metabolisms in living organisms exhibit an oscillatory character with respect to the concentration of an intermediate. Some kinds of oscillation observable on the metabolic intermediate were presumed to be due to the feedback control system in the enzymatic chain reaction, which can produce the time-retardation function. Analog computer simulation in the present study revealed an appropriateness of the above assumption. Since the feedback system has been recognized to be the universal mode for the regulation of enzymatic chain reactions in vim, it was concluded that the oscillatory behaviors in enzymatic chain reactions may not be particular but general one.