Abstract: The bed load transport rate in a river can be affected by the seepage-induced non-hydrostatic pressure distribution that is due to the difference in water level between the free surface in the river and the vicinal groundwater table.The objective of the study is to investigate the effect of seepage flows on bed load transport rates through laboratory flume experiments.The experiment focuses on the modification of dune geometry resulting from seepage flows and the celerity or the propagation of the sand dunes.The results show that the influence of flow suction on both dune celerity and height tends to be positive,while the opposite is true for the injection flow.By analysis of experimental flume data for sand dunes,qualifying the effect of seepage flows on bed load transport rates can be carried out.As the result,a modified formula for better estimating the average rate of bed load transport is proposed.