Abstract: During flood releasing from Geheyan Dam the flow in duced vibrations of the top opening gate and the bottom outlet gate in the dam were measured. The results showed that the two gates worked in perfect order, the vibration of the dam was very small. From 3.3mto 7.0 mopening a beat vibration occurred in the top opening gate, but it wasnt harmful to the gate. From 0.3mto 6.0m opening severe vibrations appeared in the bottom ou tlet gate caused by water ejecting from both sides of the gate. The side water tight seals should be renewed.