In the equilibrium reach of flow with vegetation zone along a side wall, an appreciable fluctuation of transverse velocity with low frequency appears and it brings about alternation of lateral bed-load transport. Due to the strong lateral variation of longitudinal bed-load flux, alternation of lateral bed-load transport has a net component towards the vegetation zone. A derived model of non-equilibrium bed-load transport in the lateral direction evaluates the net flux of lateral bed-load transport and the subsequent change of lateral bed profile. Movable bed experiments in the flume have been conducted, and observed sand ridge along the vegetation zone has been estimated by the analytical model.