Abstract: The first test of water-sediment regulation of the Yellow River was performed from the 9:00 A.M. on July 4 to the 9:00 A.M. on July 15,2002.The second test was conducted from the 9:00 A.M. on Sept.6 to the 6:30 P1M.on Sept118,2003.According to the test results from the Yellow River water-sediment regulation,especially the first test,the paper analyzes the results of the scouring or deposition in the lower river and the area of the river-mouth bar,the adjustment of the channel morphology,the effect of channel regulation and the changes of flowing capacity of the lower reaches.The test results show that the water-sediment regulation can reduce aggradations of the channel,increase its flowing capacity and improve the sediment delivery conditions of the channel in the lower river.Therefore,the water-sediment regulation is one of the effective measures to solve the sedimental problems of the Yellow River.