There is the feature that an ocean type earthquake has the long continuation time of an earthquake motion. This research conducts the shaking table test of a caisson type quaywall, and the feature of liquefaction of a different continuation time is examined. With the small acceleration with loose sand, the influence of continuation time is great, and after liquefaction, the pore pressure keeps high. In the case of dense sand, influence of continuation time is small, and pore pressure disappears promptly. To convert the acceleration of a scenario wave with oneof a rule wave, it is necessary to also take density into consideration.