PROBLEM TO BE SOLVED: To provide a fixing structure for a prop pipe which is certainly prevented from leaving off upward after the prop pipe is jointed with a foundation pile pipe in a manner where an upper part of the foundation pile pipe is covered with the prop pipe.SOLUTION: The fixing structure for a prop pipe comprises: a foundation pile pipe 1 fixed on the ground； a taper piece 4 having a truncated cone shape in which an upper side is expanded and fixed on the upper edge of the foundation pile pipe 1； a wedge spring 7 which winds around the periphery of the taper piece 4, whose lower edge is fixed onto the upper edge of the foundation pile pipe 1, and whose upper edge is engaged on the upper periphery of the taper piece 4 in a stretchable manner； and a prop pipe 8 into which the foundation pile pipe 1 is inserted, whose lower end part covers the foundation pile pipe 1, and whose lower edge is downwardly engaged at a predetermined position. The upper edge part of the wedge spring 7 contacts to the inner periphery of the prop pipe 8 and is compressed downwardly when the prop pipe 8 is put on so that the prop pipe 8 may put on. In addition, the wedge spring 7 is interposed between the upper periphery of the taper piece 4 and the inner periphery of the prop pipe 8 so as to prevent the prop pipe 8 leaving off upward from the foundation pile pipe 1.
