To provide a novel method of measuring a deformation of a vehicular body, in particular, a height in each part of the body, when repairing an automobile, and a vehicular body dimension measuring tool used for the measurement.

A scale rod 7 is suspended in each of a plurality of positions in the vehicular body 1 to measure the height, and a laser beam irradiation device 8 is arranged to emit a laser beam along a horizontal direction. The heights are measured in the plurality of positions of the vehicular body, by reading an irradiated position, in each scale rod, of the laser beam emitted from the laser beam irradiation device. The vehicular body dimension measuring tool 5 is projected with an attachment inserted into a reference hole, on an upper face of a measuring tool main body 6, is attached with a magnet for magnetic attraction onto the vehicular body flush with the upper face of the measuring tool main body 6 serving as a reference face for the measurement, and is suspended with the scale rods 7 in an under side of the measuring tool main body 6.