Abstract: The formulae of travelling wave resonance in a bevel gear are derived by a simplified method. Emphasis is put on the difference of physical meanings between travelling wave resonance and forced vibration resonance. The function simulating the exciting force in bevel gear is formulated by analogy of meshing force of two straight tooth gears. And then, the stress responses of travelling wave resonances of two and three nodal diameters in the bevel gear may be calculated by FEM. It is proved that the stress response curves plotted dy computer is just the curves of travelling wave resonance of two nodal diameters mode wave motion. The calculated results coincide with the experimental data. The method provided gives more convenience to obtain stress data only by calculation rather than by complicated experimental method.