A crawler tractor comprises steering mechanisms (44) (45) for rotating a machine body by causing right and left crawler belts (9) to move differentially. The tractor is characterized in that the steering mechanism (44) is connected to a drive system located behind a reverser mechanism (21) that moves the machine body forward and back. Even when the machine body movement direction is changed from forward to back, the direction of the steering wheel (18) and the direction of the rotation of the machine body are kept the same, so that a reversed steering phenomenon is prevented from occurring, and an appropriate operation in forward or back movement is enabled with a simple structure that does not require an additional mechanism such as a reverse-steering preventions mechanism.