Abstract: Floos in the lower reaches of the Yellow River are different in charatetistics due to different sources. The interaction between floods and riverbed results in the silt interchange be-tween currents and rivebed, beaches and major bed. The production levee changes the natural law of flood evolution. The spreading time and leves of floods are resricted by vdrious factors. Flood with high sediment charg has its outstanding charactetistics. As a result, flood prediction is a thoroughgoing, painstaking and complicated task.