To provide a running gear of a rubber crawler fitted on a vehicle machine and aiming at coming-off prevention of the rubber crawler due to engulfed earth sand.

The running gear of the rubber crawler comprises a drive wheel connected to the drive axle of the vehicle machine; an idling wheel; and the rubber crawler by which wrapping is effected on both the wheel and on the inner peripheral surface rubber of which protrusions are formed at specified intervals and is formed such that the drive wheel and the idling wheel are situated approximately horizontally and the rubber crawler by which wrapping is effected on this makes contact with a running surface. The drive wheel is formed in a shape that an engaging tooth with the rubber protrusion is bilaterally exposed. The running gear of the rubber crawler is provided with a guide skirt object fixed at the vehicle machine with a distance kept at the outside in the direction of the widths of the drive wheel and the wrapping section of the rubber crawler.