Abstract: Silty soil dominates the Yellow River subaqueous delta. Collapse often occurs due to the liquefaction of shallow silty soil under storm wave action. Wave flume experiments have been carried out in order to reveal the contribution factors to the collapse quantity of the liquefied silty soil bed. The soil was taken from the Yellow River. The contributions of clay migration and density increase to the collapses have been estimated. Our data shows that the contribution of clay migration is generally over 55%. The clay content of the originally homogeneous silty soil bed was redistributed and a double-segment structure formed after the liquefaction at the water-soil interface and the final and maximum liquefied interfaces respectively. The clay content increases with the increase in depth in each segment.