To provide a reinforcing part for preventing collapse which is eliminated from being projecting to the inside of a block fence.

In a concrete block fence with a reinforcing core such as a reinforcing bar, a hole is provided in the inside wall of the concrete block 1 so as to expose a part of the reinforcing core such as the reinforcing bar, a bored hole is boredly provided in the ground inside the foundation for the block fence, and a reinforcing column 7 made of a structural steel is arranged inside the block fence in such a state as covering the aforementioned hole and having the bottom end inserted in the bored hole. A port of the reinforcing column 7 matched with the hole is locked in an exposed part of the reinforcing core for the reinforcing bar by a hook bolt 8 and the bottom end of the reinforcing column 7 is fixed by casting concrete in the bored hole.