A traction control device includes: rotation speed detectors provided to wheels; a control-start determiner that determines whether or not to control a braking mechanism and a differential adjusting mechanism based on rotation speeds; a braking mechanism controller that controls the braking mechanism based on a result of the determination of the control-start determiner; and a differential adjusting mechanism controller that controls the differential adjusting mechanism based on the result of the determination of the control-start determiner, in which the control-start determiner includes: a right-left-wheel rotation speed difference calculating section; a front-rear-wheel rotation speed difference calculating section; and a control-start determining section that determines whether or not to start controlling at least one of the braking mechanism and the differential adjusting mechanism when one of rotation speed differences reaches or exceeds a predetermined threshold.