To provide a leg joint strengthening training device capable of stabilizing a walking operation by strengthening the dorsiflecion force, being applicable to the treatment of the sprain, regulating the movement in the dorsiflexing direction and the plantarflexing direction of a leg joint and regulating the lateral and medial swinging of an ankle.

This training device 1 is provided with a belt-shaped lower leg fixing belt 2 winding and fixed to a lower leg of a user, a first leg joint support part 3 having a first support belt 10 attached to the leg joint, abutting on the leg joint side face and the sole respectively, and supporting to clamp the leg joint side, and a second leg joint support part 4 having a second support belt 11.