PROBLEM TO BE SOLVED: To provide a fitting structure capable of simply fitting to a rod-like body.SOLUTION: A fitting structure 2 for fitting a sensor unit 1 as an object to a shaft 50 of a golf club 5 as a rod-like body, includes: a grip part 211 capable of storing the shaft 50 of the golf club 5 from a radially outer peripheral side; and a band 27 that is mounted on the shaft 50 of the golf club 5 in a state of being stored in the grip part 211, for preventing falling of the sensor unit 1. The shaft 50 of the golf club 5 is stored in the grip part 211, so that the shaft 50 can hold the sensor unit 1.