Based on an energy equilibrium viewpoint,the bed-load transport energy comes from the flow energy.The bed-load motion lags the flow and the consumed energy of bed load depends on the relative motion between the flow and particles.A bed-load transport relation is deduced.According to the experimental data,the influential factors of the parameters of the bed-load transport relation are determined.Using the experimental data,the parameters of the bed-load transport relation are validated.The formula is in good agreement with the experimental data with higher accuracy.