To provide a random winding preventive device of a hoisting device capable of improving reliability, by preventing random winding and falling-off caused by tension reduction in a rope body with a simple structure.

An arm member 9 is composed of a winding arm 7 and a weight arm 8 extending in a substantially V shape with the axial center O of a hoisting drum 6 as the origin, and is rotatably arranged with the axis of the hoisting drum 6 as the center. This random winding preventive device 15 is constituted by arranging a guide frame 13 extending in parallel to the axis of the hoisting drum 6 and inserting the rope body 3 delivered from the hoisting drum 6 in a tip part of the winding arm 7 of the arm member 9, arranging a weight 14 in a tip part of the weight arm 8 of the arm member 9, and making the moment M act on the arm member 9 for rotating the arm member 9 in the opposite direction of the rope body winding rotating direction R of the hoisting drum 6.