Abstract: The relationship betweenwheel/rail(W /R) corrugation and thewavelength of longitudinal self-vibration and the longitudinal axis of contactellipsewas analyzed based on the nonlinear vibration and Hertzian theories. The analysis shows that the mechanism of W /R corrugation is that the wavelength of longitudinal self-vibration is larger than the longitudinal axis ofcontactellipse; for a real W /R system, the criterion is that the lateral displacement of the wheelset is larger than a critical value. Numerical simulation and testwere conducted to verify the proposedmechanism and criterion. The simulation results show thatcorrugationswith lengthsbetween 16 to20mm appearwhen the lateral displacementof thewheelset is 8 mm. Corrugation testwas conducted on a rolling vibration test rig. Corrugations form when the lateraldisplacements of thewheelsetare 8 and 11mm, and the lengths are about20 mm and 18 to 27 mm, respectively, under the former and the latter conditions. There is no obvious corrugationwhen the lateral displacement is 6 mm.