Abstract: Phosphorus (P) is a major pollutant in Chinese rivers．Sediments affects the migration process of P at sediment-water interface, but the mechanism is not entirely clear．In the present work, 18 water samples and 2 sediment core samples were taken in October 2019 along the Yellow River, a river with typically high sediment and phosphorus loads, which has important research significance for the migration process of phosphorus in river．Total phosphorus (TP) and sediment contents in water, and phosphorus contents in different forms in sediment were measured．These data were correlated with hydrological data (sediment transport, sand content, suspended sediment particle size) from 2000-2019．Sediment-transport in the middle-reaches of the river showed significant downward trend in the past 20 years, but remained stable downstream．Sediment content front downstream showed upward trend．In synergistic analysis, sediment content and TP in the lower reaches showed opposite change patterns．Resuspension of largerdiameter sediments due to scouring was found to have significant effect on the migration of phosphorus．IP was found to be the most prominent, with Ca-P being the main form of IP．Fe/Al-P migrated at the sediment-water interface when flow velocity was slow．Besides, sediment load was low and resuspension of sediment was weak．When at a high flow rate, the water body has a high sediment content and the resuspension of the sediment was strong．Downstream sediment and suspended particles become a phosphorus sink．