Abstract: The centrifugal experiments are carried out to study the dynamic responses of suction buckets in fine silty sand under horizontal loading. The static bearing capacity after dynamic loading is investigated too. If there is a clay over-layer whose surface is at the same level with the bucket’s top, the settlements of bucket and sand layer are bigger than that without an over-layer, but the increment of pore pressure is on the contrary. The static bearing capacity of the bucket increases after dynamic loading. With the increase of loading amplitude, the settlement of sand layer increases, but the affected zone with obvious deformation is limited (about one times the bucket’s height)because of the filtering and decaying effects of the liquefaction zone on the vibration. The excess pore pressure decreases from the bucket’s edge to the inside and from the surface of sand layer to the bottom. The complete liquefaction thickness of the sand layer increases with the increase of load amplitude whose maximum is about 40% of the bucket’s height.