Following the previously reported experiments, an experimental study on the liquefaction of saturated Shirasu using shaking sand box was carried out. It was concluded from these experiments that the stress condition in which saturated Shirasu liquefied was almost the same as in the case of Toyoura sand. Besides, taking advantage of the fact that, at this shaking table, the frequency of the vibration could be changed automatically and periodically within the range of the frequency previously set up, experiments under variable acceleration was carried out and its effect on the liquefaction of soil was inquired. It was clarified as a result that the average equivalent acceleration α_<aυ> could be calculated from the formula (3).