A draft control device of tractor includes a top link fixing bracket fixed at the rear side of the tractor, a top link swing bracket hinge-coupled to the top link fixing bracket through a connection pin, and carrying out rotational motion with respect to the axial center of the connection pin according to the change of the compressive force of a top link in response to the change of work machine traction resistance, a leaf spring provided between the top link fixing bracket and the top link swing bracket to supply restoring force for the rotational motion of the top link swing bracket with respect to the top link fixing bracket, and a sensitivity adjustment unit provided between the top link swing bracket and the leaf spring, and changing an acting point, where the top link swing bracket pushes the leaf spring, to adjust work machine traction load sensitivity.
