Abstract: According to the characteristics of coming water and sediment,evolution of erosion and deposition of channel in the Yellow River mouth reach,the onedimensional mathematical model of water and sediment routing is developed from downstream Lijing station,considering ununiformity of flow and sediment in cross section,flow friction,extension of river mouth delta.The model is used to compute flow and sediment transport and river channel.The results agreed with the field data.The model can be used to predict the water level,sediment concentration,erosion and deposition in the Yellow River mouth reach.