This study is a deepening of cognition and supplement to the research contents on radial gates installed at the TGP divesion bottom outlets for "Ninth Five-year-plan" science technology key-tackling items of our country. The vibration diminishing measures for gates were further studied by optimizing their structural configuration. The flow-induced vibration tests for the optimum alternative were conducted on a full hydroelastic model with scale 1∶20, for estimating the vibrationdi-minishing effect and assessing its influences on dynamic properties of the gates. The test results showed that the vibration-diminishing effect of the optimum alternative is obvious, and these results may be used as reference for similar submerged-outlet gates.