A walking assistance device (1) has a body-mounted assembly (2) installed on the waist of a user (A), foot-mounted assemblies (3L, 3R) installed on feet, and leg links (4L, 4R) which connect the foot-mounted assemblies (3L, 3R) to the body-mounted assembly (2). The foot-mounted assemblies (3L, 3R) are provided with floor reaction force sensors (13L, 13R). Results obtained by multiplying the absolute values of floor reaction force vectors (three-dimensional vectors) detected by the floor reaction force sensors (13L, 13R) by a predetermined ratio are defined as target values of the magnitudes of the supporting forces transmitted to the leg links (4L, 4R) from the foot-mounted assemblies (3L, 3R). Actuators (20L, 20R) of the leg links (4L, 4R) are controlled such that the supporting forces having the magnitudes of the target values act on the leg links (4L, 4R) from the foot-mounted assemblies (3L, 3R) through the intermediary of joints (19L, 19R).