Abstract: An experimental investigation on a model of rotor support system with Elastic Ring Squeeze Film Damper (ERSFD) was completed in the case of supplying oil for the squeeze oil film damping during rotor system operation.The dynamic characteristic experiments including vibration damping and frequency retuning characteristics of the model of rotor support system with EQSFD were conducted.It is proved true that the ERSFD possesses very good properties for both vibration damping and freqnency retuning.At last,the ERSFD has been used successfully in the rotor system of a given core aero-engine.It is indicated that the ERSFD can adjust the critical speeds of the rotor system to meet the demands of engine operation and control the vibration of whole core engine very well.