Abstract: A wheel rim displacement measuring apparatus which measures radial and axial displacements of a rim wall on the basis of a nut seat pitch circle. A wheel to be measured is mounted on a lower head on the basis of a hub hole center and rotated about an axis of the lower head. An upper spindle which is horizontally displaceable relative to the lower head is adjusted in position so as to align with a nut seat pitch circle center of the wheel and is rotated about the axis of the lower head. A Fourier analysis is carried on a wave of the displacements of the upper spindle so that an eccentricity amount of the nut seat pitch circle center from the hub hole center of the wheel can be calculated from the first harmonic. In a computer, a wave of the displacements of the rim wall measured on the basis of the hub hole center is amended in calculation to a wave of the displacements of the rim wall from a true circle having a center at the nut seat pitch circle using the first harmonic wave.