We investigated the persistence of the most intense Jovian decameter bursts observed during 17 consecutive years (1974–1990). The results showed that even the most intense group of decametric storms lasted only one-earth-day or less. When we assume that the persistence of the Jovian decametric radio storms indicate the duration of the Jovian magnetospheric disturbance, the result implies that even the large Jovian magnetospheric disturbance appears in a major singular event without sequential activities. From this argument, it would be supposed that the Jovian magnetosphere unloads the stored magnetospheric energy in a burst and has no geomagnetic storm-like disturbance.