Abstract: A type of radial composite piezoelectric ceramic ring transducer in flexural vibration is presented and its flexural vibration is studied.The transducer is composed of a radially polarized piezoelectric ceramic ring and a metal ring.Using the energy method,the resonance frequency and the effective electromechanical coupling coefficient are obtained.The impacts of the geometries of the composite ring on its performance are also investigated.As the thickness of metal ring increases,the resonance frequency also increases,while the effective electromechanical coupling coefficient has a maximum value.Then the finite element analysis is carried out and two transducers are assembled and measured.It is shown that the theoretical predictions agree well with the simulated and experimental results.The composite circular ring transducer has evident advantages compared with pure piezoelectric ceramic one.