PURPOSE: To improve working efficiency, in a reverse type working vehicle which performs work by rotating a seat forward and backward, by rotating the seat forward and backward around a seat pivotally supporting shaft and also right and left steering levers disposed on the front of the seat at the same time.

CONSTITUTION: If a lock lever 3 is rotated upward, steering levers 1, 2, a rotat ing side lock body 17, engagement pin arms 33, 34, and engagement pins 5, 6 rise while sliding around a seat support shaft 19 at the same time by pull-up link 14, and the engagement pins 5, 6 of the engagement pin arms 33, 34 get out of the engagement recessed part of switching arms 7, 8, and the same time, a lock pin 4 on the lower surface of the rotating side lock body 17 gets out of a lock pin hole. Under this condition, a seat S, the steering levers 1, 2, the rotating side lock body 17, and the lock lever 3 are rotated backward at the same time. Under this rotating condition, the lock lever 3 lowers, the lock pin 4 is fitted into lock pin hole, and the engagement pins 5, 6 of the engage ment pin arms 33, 34 are fitted into the switching arms 8, 7 reversely.