Abstract: The finite element method for the computation of natural frequencies of revolution bellows considering the coupling effect between bellows and liquid was developed.The revolution bellows was idealized as a series of conical frusta,joined at nodal circles.The variables,such as displacements and loads,were expanded into Fourier series in the circumferential direction.Then the twodimensional problem was reduced to a series of onedimensional problems.The computation time was reduced.Based on the theory of fluid mechanics and the finite element method,the free vibration equations,considering the coupling effect between bellows and liquid,for the bellows was derived.The natural frequencies of the bellows were computed.The results can be used as the theoretical base for the dynamic design of bellows in engineering.