Abstract: Silty seabed would liquefy under wave action and this process includes two stages, liquefaction development and liquefaction deposits. In this paper, a wave flume experiment is made on a sediment bed consisting of silty soil for acquiring the data on variation in water content, clay content, median grain size, density and penetration resistance in the process of liquefaction in order to study the physical and mechanical properties changes in the liquefaction process. It is observed that the silty soil liquefaction development process is marked by the decrease in soil strength, soil density, median size and clay content, and increase in water content. During the liquefaction deposits process, however, the soil strength, soil density and median size increase, while the water content and clay content decrease.