To provide a variable lead rolling body screw device capable of moving a nut fast or slowly, while continuously rotating a screw shaft at constant speed, and restricted in friction resistance.

This rolling body screw device is provided with the screw shaft 1 formed with a spiral ball rolling groove, in which lead is changed in different axial positions and balls 4 roll, a ball holding member 8 having a ball rolling groove 8d, in which the balls 4 roll, a case 7 for rotatably housing the ball holding member 8, and a plurality of balls 4 interposed freely to roll between the ball rolling groove 2 of the screw shaft 1 and the ball rolling groove 8d of the ball holding member 8. When relatively rotating the screw shaft 1 in relation to the case 7, the ball holding member is rotated in relation to the case 7 in response to a change of lead of the screw shaft 1.