A generated torque control method for a leg body exercise assistive apparatus enabling a person to make a leg motion in such a feeling that the person is not wearing the leg body exercise assistive apparatus as much as possible by reducing the weight of the leg body exercise assistive apparatus attached to the person acting on the person. On the assumption that a person (A) not wearing the assistive apparatus (1) is making the same motion as a leg motion of the person (A) wearing the leg body exercise assistive apparatus (1) during the leg motion of the person (A), an estimation is made for a person-side joint moment to be generated in each joint of the leg of the person (A), and on the assumption that the assistive apparatus (1) is independently making the same motion as the leg motion, an estimation is made for an apparatus-side joint moment to be generated in the joint regions (4), (6), and (10) of the leg sections of the assistive apparatus (1). The estimated value of the apparatus-side joint moment is considered as a reference torque for torque generation means (18), (19), and (20), and a torque formed by adding a torque according to the estimated value of the person-side joint moment to the reference torque is generated in the torque generation means (18), (19), and (20).