A fitting method, of a shaft of a golf club, for selecting a shaft having a torque matching a golfer based on a swing of the golfer. The method includes the steps of obtaining measurement values from a sensor attached to a grip of the golf club and capable of measuring angular velocities about three axes when a golf ball is hit by the golf club obtaining a predetermined index value for the angular velocities quantified from the measurement values and selecting a shaft matching the golfer from among multiple shafts whose torques have been measured in advance, based on a relationship established through test-hitting performed in advance between the index value and a torque of a shaft.
