A series of 1-g shaking-table model tests was carried out on lateral flow of a sandy slope undergoing high excess pore water pressure. Model sandy deposit of extremely low density was prepared in order to induce lateral flow to various extents whether with continued shaking or impact shaking of short duration. By changing the test conditions, the effects of the intensity of shaking, the frequency of base excitation, the slope angle, and the density of sand were investigated. To facilitate the further development of an analytical measure that predicts the liquefaction-induced lateral flow movement, a simple model was developed with a rate-dependent energy dissipation mechanism. Example calculations showed that the experimental findings in the shaking table tests were reproduced by this model.