To provide a dropout preventing clip which quickly and positively performs prevention of lifting and dropout of a Kaiser truss member embedded in a precast concrete thin floor slab in the process of manufacturing the floor slab, in place of a conventional reinforcing means.

The locking clip is formed by bending a thin but tough wire, which pinches an intersection between part of a reinforcement of the thin floor slab and a lower chord of the Kaiser truss reinforcement. Thus the intersection is fixed and therefore the lifting and disengagement of the Kaiser truss member are prevented.