PROBLEM TO BE SOLVED: To provide a work control device of a tractor which can be used according to a field condition and a worker's preference even when a load is applied on an engine and can improve work efficiency.SOLUTION: The tractor includes selection switches 201, 203 selecting a fuel economy priority mode prioritizing fuel economy over tillage dept of a tillage dial 133 and a work priority mode prioritizing the tillage depth of the tillage dial 133 over the fuel economy. The tractor includes a work control device performing control such that tillage depth control is performed which lifts/lowers a work machine 120 to perform the tillage depth of the tillage depth dial 133, and when a load is a predetermined value or larger in the tillage depth control, the load being determined from a fuel injection amount for controlling an engine speed in a set speed based on a target speed, the tillage control is not maintained and the work machine 120 is lifted in the fuel economy priority mode being selected, on the other hand, load control maintaining the tillage control is performed in the work priority mode being selected. Accordingly, the selection switches 201, 203 enable the tractor to be used according to a field condition and a worker's preference.SELECTED DRAWING: Figure 9
