To provide a binding structure for a paper bundle in which punched holes and cut holes are formed on a plurality of paper sheets and joined portions are formed by inserting cut and raised pieces which are cut and raised from the punched holes into the cut holes, so as to bind the plurality of paper sheets to each other, wherein the binding structure for the paper bundle is capable of solving the problem that the cut and raised piece and the cut hole which are joined to each other are easily detached from each other.

In the binding structure for the paper bundle B, the punched holes P1 and the cut holes P2 are formed on the plurality of paper sheets P and joined portions P3 are formed by inserting the cut and raised pieces P4 which are cut and raised from the punched holes P1 into the cut holes P2, so as to bind the plurality of paper sheets P to each other. Relief slits P5 for alleviating application of force added when the relative positions of the paper sheets P are changed to the joined portion P3 are provided in portions adjacent to the joined portion P3.