PURPOSE: To provide a rolling control mechanism of a ground working machine, capable of excellently finishing a ground work even in a soft field without requirement for a switching operation of the rolling control condition.

CONSTITUTION: When detecting a forced elevating operation of a ground working machine 2 by an oil-hydraulic cylinder 3 for elevation drive simultaneously with detection of elevation of the ground working machine 2 to a position higher than a preset level relative to the running machine body, the ground working machine 2 is controlled so as to be kept parallel to the running machine body in the right and left directions with priority to a rolling control operation for keeping the ground working machine 2 in an inclined posture from the ground in the right and left directions.