Abstract: A dynamic determination method based on cantilever resonance was presented to solve the crude and material-damage problems of current ways in measurement of IPMC Young's modulus. An incentive device was applied to bring the IPMC into the damping free vibration state, which was recorded by a laser displacement sensor. The fundamental frequency was obtained by analyzing and processing the collected signal. A transverse vibration equation was established on the basis of the cantilever resonant vibration, and the IPMC Young's modulus can be then calculated by introducing boundary conditions. Compared with the existing tensile and bending tests, the proposed method has advantages of convenience and simpleness, non-destructive testing and high measurement accuracy.