Abstract: Since 2002, centralized water and sediment regulation was carried out during the period of above- flood- level water preflood discharge and clearing out the flood control storage capacity. Great deposit mitigation benefit was gotten from this. During the regulation of water and sediment, as result of large volume discharge and reservoir water level fell fast, dam deformation increased. It was of the characteristics that the horizontal displacement changed to the upstream and the vertical displacement settlement accelerated. Monitoring results showed that the water and sediment regulation would not affect the damsafety and operation.