To provide a traveling device achieved in the spline joining of a spindle and a carrier of a planetary reduction mechanism.

This traveling device has the planetary reduction mechanism 7 for reducing the rotation of a traveling motor 6, and a wheel 10 supported via a tapered bearing 9 by the spindle 8 forming a wheel shaft and rotating by the planetary reduction mechanism 7, and is provided so that the planetary reduction mechanism 7 includes a sun gear 13 rotating by the rotation of a shaft 12 of the traveling motor 6, a planetary gear 18 rotating the wheel 10 according to the rotation of the sun gear 13, a stepped pin 20 forming a rotary shaft of the planetary gear 18, the carrier 21 holding a stepped pin 20, and a bolt 22 fixing the stepped pin 20 to the carrier 21, and comprises a spline joining part 23 for joining the spindle 8 and the carrier 21, and a regulating member for regulating movement in the direction approaching a tapered bearing 9 of the bolt 22.