To provide a braking device for a towed vehicle which can increase the braking force at the advance time and facilitate the removal of the generation of the braking force at the reteat time.

This device is composed of a frame body F for loading a small vehicle and a connection body C for connecting the frame body F to a tractor. The frame body F is provided with a pair of wheels 12, 12 and a brake disc 9 inside each wheel 12 and constituted so as to push-press the brake disc 9 to the wheel 12 side by a brake wire 7 connecting to a connection metal fitting 6 for operating the brake disc 9. The connection body C is composed of a connection frame 2 for supporting the slide shaft 3 fixed to the connection tool 1 mounted on a tractor, a shock absorber 4 operated by the reteat of the slide shaft 3 and a counter lever 5, mounted on the connection frame 2 turnably and turned in front/rear direction by the slide shaft 3, which can move the connection metal fitting 6 in front/rear direction.