Abstract: A folding and positioning device for tier-seats comprising several linked seats 1 in the same row with their pedestals 3. At least one rotational leg 2 is fixed in the middle on the rotational shaft 7 on the upper front side inside the pedestal, its upper end fixed on the seat 1 and the lower end having a step. In the lower rear inside the pedestal is another rotational shaft 5, on which is fixed a bracketing arm 6 in the position corresponding to the rotational leg 2. When the seats are being erected to their upright position, the free end of the bracketing arm 6 abuts against the step at the lower part of the rotational leg 2. Compared with conventional technologies, the present invention calls for very little force in order to erect or lay down the seats. Furthermore, the seats in the entire row are linked joint motion, thus greatly enhancing the efficiency.