The experiment study on influence of TGP regulation the peak flood to the navigational condition between Two Dams shows: The regulation peak has the characteristic with large discharge,widely discharge variation and water level fluctuant and so on.During the adjust peak,the velocity and slope during two dams are higher than low water evidently,and the influence on navigation is obvious.When the released discharge diurnal average is between 10 000 and 15 000 m~(3)/s,the navigation condition can meet the requirement of 10 000 T ship team,but when the discharge exceed 20 000 m~(3)/s,the velocity and slope at important bar between two dams are near or over the allowable value,the upward ship team sail difficultly.