Water-sediment regulation of the Yellow River is to regulate and control the flow and sediment transport relationship of the lower reaches through reservoirs on the main streams and tributaries to create balance between water and sediment so that sediment transport capacity of the downstream channels can be maximized,shrinking of channels be contained,and medium flood channel be restored and maintained.Many years’ research by the Yellow River Conservancy Commission(YRCC) reveals the water and sediment transport relationship that will prevent sedimentation at the downstream river channels.Based on this relationship and coming sediment and water conditions in the Yellow River basin,the YRCC,with maximized use of reservoirs on the main streams and tributaries,has developed three models of water-sediment regulation:single Xiaolangdi Reservoir-dominated regulation,space scale water-sediment match,and mainstream reservoirs joint operation.Ten water-sediment regulations based on these three models have resulted in an average drop of 1.5 m in the main channel of the downstream 800 km river and an increase of carrying capacity from 1800 to 4000 m3/s.Besides,the wetland ecosystems of estuarine delta has also been improved and restored significantly. Water-sediment regulation of the Yellow River is to regulate and control the flow and sediment transport relationship of the lower reaches through reservoirs on the main streams and tributaries to create balance between water and sediment so that sediment transport capacity of the downstream channels can be maximized , shrinking of channels be contained, and medium flood channel be restored and maintained. Many years’ research by the Yellow River Conservancy Commission (YRCC) reveals the water and sediment transport relationship that prevent preventative sedimentation at the downstream river channels. and coming sediment and water conditions in the Yellow River basin, the YRCC, with maximized use of reservoirs on the main streams and tributaries, has developed three models of water-sediment regulation: single Xiaolangdi Reservoir-dominated regulation, space scale water-sediment match , and the latter reservoirs joint operation. Ten water-sediment regulations based on these three m odels have resulted in an average drop of 1.5 m in the main channel of the downstream 800 km river and an increase of carrying capacity from 1800 to 4000 m3 / s.Besides, the wetland ecosystems of estuarine delta has also been improved and restored significantly.